IFOKNL- 


WASPS 

SOCIAL  AND  SOLITARY 


Pagez66 

PELOP/EUS  ON    NEST,    GROUP   OF   FINISHED   CELLS,  AND    TUBE   OPENED 
TO   SHOW   SPIDERS 


WASPS 

SOCIAL    AND    SOLITARY 

BY 

GEORGE    W.    PECKHAM 

AND 

ELIZABETH    G.    PECKHAM 

WITH    AN    INTRODUCTION    BY 

JOHN    BURROUGHS 

ILLUSTRATIONS  BY  JAMES  H.   EMERTON 
"  Bold  sons  of  air  and  heat,  untamed,  uutired."  —  ILIAD,  Book  XVII 


BOSTON   AND   NEW   YORK 
HOUGHTON,   MIFFLIN   AND   COMPANY 

j,  Cambtib0e 
1905 

15670 

1907 


COPYRIGHT    1905   BY   GEORGE  W.  PECKHAM   AND   ELIZABETH   G.   PECKIIAM 
ALL   RIGHTS   RESERVED 


Published  April,  1905 


NOTE 

A  PART  of  the  matter  presented  in  this  volume  was 

published  several  years  ago  by  the  Wisconsin  Biological 

Survey,  under  the  title  "Instincts  and  Habits  of  the 

Solitary  Wasps."     These  chapters  have  been  revised 

and  modified,  and  new  matter  based  upon  later  work 

rNias  been  added,  in  the  hope  that  in  their  present  less 

JvXtechnical  form  the  observations  recorded  will  be  of  in- 

^,  terest  to  the  general  reader. 

For  a  number  of  the  text  cuts  used  in  this  volume  we 
are  indebted  to  the  courtesy  of  Dr.  E.  A.  Birge,  Direc- 
tor of  the  Wisconsin  Geological  and  Natural  History 
Survey. 


CONTENTS 

CHAPTER  PAGE 

I.   COMMUNAL  LIFE i  , 

II.   AMMOPHILA  AND  HER  CATERPILLARS         .  15 

III.  THE  GREAT  GOLDEN  DIGGER       .        .  .      56^' 

IV.  SEVERAL  LITTLE  WASPS    .        .        .        .  72 
V.    CRABRO .97 

VI.   AN  ISLAND  SETTLEMENT  .         .        .  119 

VII.   THE  BURROWERS 141 

VIII.   THE  WOOD-BORERS 178 

'IX.   THE  SPIDER-HUNTERS  .        >        .        .  .     196 

X.   THE  ENEMIES  OF  THE  GRASSHOPPER         .  248 

XI.   WORKERS  IN  CLAY        .                 .        .  -265 

XII.    SENSE  OF  DIRECTION         ....  275 

XIII.   INSTINCT  AND  INTELLIGENCE         .        .  .292 


LIST   OF   ILLUSTRATIONS 

PAGE 

PELOP^EUS  ON  NEST,  GROUP  OF  FINISHED  CELLS,  AND 

TUBE  OPENED  TO  SHOW  SPIDERS  (page  266)  Frontispiece 

WASP  EATING 3 

PAPER  NEST  WITH  SIDE  REMOVED  jo  SHOW  CON- 
STRUCTION OF  COMBS ii 

AMMOPHILA  URNARIA  CARRYING  CATERPILLAR   TO 

NEST 19 

AMMOPHILA  URNARIA  STINGING  CATERPILLAR     .  27 

CATERPILLAR  WITH  EGG  OF  AMMOPHILA  URNARIA  29 

NEST  OF  AMMOPHILA 31 

AMMOPHILA  URNARIA  USING  STONE  TO  POUND  DOWN 

EARTH  OVER  NEST            39 

THOROUGH  LOCALITY  STUDY  BY  SPHEX        .        .  59 
HASTY  LOCALITY  STUDY  BY  SPHEX          .         .         .61 

SPHEX  DRAGGING  GRASSHOPPER  TO  HER  NEST     .  63 

NEST  OF  SPHEX 69 

OXYBELUS  QUADRINOTATUS 75 

NEST  OF  OXYBELUS 79 

APORUS  FASCIATUS 81 

WASP  HOMES  IN  THE  LOG  CABIN  ....  85 

NEST  OF  PERENNIS      .        .        .        .        *}      •  89 
NEST  OF  ANORMIS  .        .                 .        .        .        .91 


LIST   OF   ILLUSTRATIONS 

PAGE 

SEXMACULATUS  IN  THE  LINDEN  ROOTS        .        .99 
CRABRO  AND  HER  WHITE  MOTHS    .        .        .        .103 

CRABRO  STIRPICOLA 106 

BOTTLE  ON  STEM  TO  MEASURE  WORK  OF  CRABRO  .     107 

NEST  OF  C.  STIRPICOLA 113 

AMMOPHILA     SLEEPING     IN     THE    GRASS     (AFTER 

BANKS)     .        .        .        .        .        .        .        .115 

NEST  OF  BEMBEX 125 

BEMBEX  SPINOL^;  LOOKING  OUT  OF  NEST        .        -131 

BEMBEX 136 

A  CORNER  OF  THE  BEMBEX  COLONY      .        .        .137 
NEST  OF  CERCERIS  NIGRESCENS  .        .        .        .        142 
CERCERIS  CLYPEATA         .        .        .        ..     ~.        .143 
CERCERIS  DESERTA  :  LOCALITY  STUDY  BEFORE  LEAV- 
ING NEST 153 

PHILANTHUS  PUNCTATUS          .        .        .        .        .157 
NEST  OF  PHILANTHUS  PUNCTATUS       .        .        .         163 
APHILANTHOPS  GATHERING  ANTS    .        .        .        .169 
TRYPOXYLON  RUBROCINCTUM        .        .        .        .         185 
MALE  TRYPOXYLON  AWAITING  THE  FEMALE    .        .191 
TORNADO  WASP  (POMPILUS  QUINQUENOTATUS)  DIG- 
GING NEST     .        .  .        .        .  197 
POMPILUS  QUINQUENOTATUS    .        .        .        .        .     199 
EPEIRA  STRIX  PARALYZED  AND  HUNG  UP  ON  BEAN 
PLANT  BY  POMPILUS  QUINQUENOTATUS,  OUT  OF 

THE  WAY  OF  ANTS 203 

NEST  OF  P.  QUINQUENOTATUS         .        .  .213 

POMPILUS  MARGINATUS 223 


LIST   OF   ILLUSTRATIONS 

PAGE 

THE  HOME-COMING  OF  SCELESTUS  .         .        .        .241 
NEST  OF  AGENIA  BOMBYCINA       ....         245 
LYCOSA  KOCHII,  FOUND  IN  NEST  OF  AGENIA  BOM- 
BYCINA       245 

TACHYTES 249 

NEST  OF  TACHYTES 251 

CHLORION  AND  THE  INDISCREET  CRICKET  .         .         257 
HORIZONTAL  CELLS  OF  THE  MUD-DAUBER      .         .271 

COURSE     FOLLOWED     BY     POMPILUS     FUSCIPENNIS     IN 

FINDING  HER  SPIDER,  AND  IN  RETRACING   HER 

STEPS  TO  THE  NEST 283 

LOCALITY  STUDY  OF  ASTATA  BICOLOR          .        .  288 

LOCALITY  STUDY  OF  ASTATA  UNICOLOR  .        .        .  289 

SECOND  LOCALITY  STUDY  OF  ASTATA  UNICOLOR  290 
PARALYZED  SPIDER  HUNG  UP  ON  SORREL  BY  QUIN- 

QUENOTATUS  WHILE  SHE  DIGS  HER  NEST      .  295 


Introduction 

NOT  long  since  I  wrote  to  a  friend,  a  nature  lover, 
as  follows:  "The  most  charming  monograph  in 
any  department  of  our  natural  history  that  I  have  read 
in  many  a  year  is  on  our  solitary  wasps,  by  George 
W.  Peckham  and  his  wife,  of  Wisconsin,  —  a  work  so 
delightful  and  instructive  that  it  is  a  great  pity  it  is 
not  published  in  some  popular  series  of  nature  books, 
where  it  could  reach  its  fit  audience,  instead  of  being 
handicapped  as  a  State  publication."  This  end  has  now 
been  brought  about,  and  the  book —  revised  and  enlarged 
with  much  new  material  and  many  new  illustrations  — 
placed  within  easy  reach  of  all  nature  lovers,  to  whom  it 
gives  me  pleasure  to  commend  it/It  is  a  wonderful  record 
of  patient,  exact,  and  loving  observation,  which  has  all  the 
interest  of  a  romance.  It  opens  up  a  world  of  Lilliput 
right  at  our  feet,  wherein  the  little  people  amuse  and 
delight  us  with  their  curious  human  foibles  and  whim- 
sicalities, and  surprise  us  with  their  intelligence  and 
individuality.  yHere  I  had  beeri  saying  in  print  that  I 
looked  upon  insects  as  perfect  automata,  and  all  of  the 
same  class  as  nearly  alike  as  the  leaves  of  the  trees  or 


INTRODUCTION 

the  sands  upon  the  beach.  I  had  not  reckoned  with  the 
Peckhams  and  their  solitary  wasps.  The  solitary  ways 
of  these  insects  seem  to  bring  out  their  individual  traits, 
and  they  differ  one  from  another,  more  than  any  other 
wild  creatures  known  to  me.  It  has  been  thought  that 
man  is  the  only  tool- using  animal,  yet  here  is  one  of  these 
wasps,  Ammophila,  that  uses  a  little  pebble  to  pound 
down  the  earth  over  her  nest.  She  takes  the  pebble  in 
her  mandibles,  as  you  or  I  would  take  a  stone  in  our 
hand,  and  uses  it  as  a  hammer  to  pound  down  the  soil 
above  the  cavity  that  holds  her  egg.  This  is  a  remark- 
able fact ;  so  far  as  I  know  there  is  no  other  animal  on 
this  continent  that  makes  any  mechanical  use  of  an 
object  or  substance  foreign  to  its  own  body  in  this  way. 
The  act  stamps  Ammophila  as  a  tool-using  animal. 

I  am  free  to  confess  that  I  have  had  more  delight  in 
reading  this  book  than  in  reading  any  other  nature  book 
in  a  long  time.  Such  a  queer  little  people  as  it  reveals  to 
us,  so  whimsical,  so  fickle,  so  fussy,  so  forgetful,  so  wise 
and  yet  so  foolish,  such  victims  of  routine  and  yet  so 
individual,  with  such  apparent  foresight  and  yet  such 
thoughtlessness,  finding  their  way  back  to  the  same 
square  inch  of  earth  in  the  monotonous  expanse  of  a 
wide  plowed  field  with  unfailing  accuracy,  and  then  at 
times  finishing  their  cell  and  sealing  it  up  without  the 


INTRODUCTION 

spider  and  the  egg ;  hardly  any  two  alike ;  one  nervous 
and  excitable,  another  calm  and  unhurried ;  one  care- 
less in  her  work,  another  neat  and  thorough ;  this  one 
suspicious,  that  one  confiding ;  one  species  digging  its 
burrow  before  it  captures  its  game,  others  capturing  the 
game  and  then  digging  the  hole ;  one  wasp  hanging  its 
spider  up  in  the  fork  of  a  weed  to  keep  it  away  from  the 
ants  while  it  works  at  its  nest,  and  then  running  to  it 
every  moment  or  two  to  see  that  it  is  safe  ;  another  lay- 
ing the  insect  on  the  ground  while  it  digs,  —  verily  a 
queer  little  people,  with  a  lot  of  wild  nature  about  them, 
and  of  human  nature,  too. 

JOHN  BURROUGHS. 


WASPS 

Social  and  Solitary 


Chapter    I 

COMMUNAL   LIFE 


"  For  where  's  the  state  beneath  the  firmament 
That  doth  excel  the  wasps'  for  government." 

"  What  is  not  good  for  the  swarm  is  not  good  for  the  wasp. 


\  S  the  tendency  of  mankind  to  crowd  into  towns 
JL  \.  grows  stronger  the  joys  of  country  life  and  the 
workings  of  Nature  are  more  and  more  excluded  from 
the  daily  experience  of  humanity.  In  a  few  the  primal 
love  of  the  wild  is  too  strong  for  suppression,  and  turning 
from  the  hot  and  noisy  streets  they  find  it  a  refreshment 
of  spirit  to  meet  our  little  brothers  of  earth  and  air  in  the 
wider  spaces  of  their  own  territory. 

We  were  walking  through  the  woods  one  hot  day  in 
the  middle  of  August  when  our  attention  was  attracted 
by  a  stream  of  yellow-jackets  issuing  from  the  ground. 
They  came  in  such  surprising  numbers  and  looked  so 


WASPS,  SOCIAL  AND   SOLITARY 

full  of  energy  that  we  stopped  to  watch  them,  and  this 
was  our  introduction  to  the  study  of  these  "bold  sons  of 
air  and  heat,"  although  a  perusal  of  Fabre's  fascinating 
"Souvenirs  Entomologiques "  had  prepared  us  to  feel  a 
lively  interest  in  them.  We  were  at  our  summer  home 
near  Milwaukee,  where  meadow  and  garden,  with  the 
wooded  island  in  the  lake  close  by,  offered  themselves  as 
hunting  grounds,  while  wasps  of  every  kind,  the  social- 
istic tribes  as  well  as  the  extreme  individualists  of  the 
solitary  species,  were  waiting  to  be  studied. 

The  Vespas  that  had  aroused  our  interest  received  our 
first  attention,  and  a  nest  in  the  ground  proved  to  be  a  most 
convenient  arrangement.  Experiments  that  would  have 
been  dangerous  to  life  and  limb  had  we  tried  them  with 
a  paper  nest  hanging  in  the  open,  were  easy  here  so  long 
as  we  kept  calm  and  unflurried.  Intent  upon  their  own 
affairs,  and  unsuspicious  of  evil,  perhaps  because  they 
knew  themselves  to  be  armed  against  aggression,  they 
accepted  our  presence,  at  first  with  indifference;  but  as 
we  sat  .there  day  after  day  we  must  have  become  land- 
marks to  them,  and  perhaps  before  the  summer  was 
over  they  considered  us  really  a  part  of  home. 

While  poor  humanity  takes  comfort  in  a  mid-day 
siesta,  wasps  love  the  heat  of  noontide,  and  with  every 
rise  in  temperature  they  fly  faster,  hum  louder,  and 


COMMUNAL  LIFE 

rejoice  more  and  more  in  the  fullness  of  life,.  The  en- 
trance to  the  Vespa  nest  was  but  an  inch  across ;  and  once 
when  they  were  going  in  and  out  in  a  hurrying  throng, 
jostling  each  other  in  their  eagerness,  we  counted  the 
number  that  passed,  one  taking  the  entrances  and  one 


WASP    EATING 


the  exits.  In  ten  minutes  five  hundred  and  ninety-two 
left  the  nest  and  two  hundred  and  forty-seven  went  in, 
so  that  we  saw  eight  hundred  and  thirty-nine  or  about 
eighty  to  the  minute.  This  must  be  a  strong  swarm, 
wonderful  indeed  when  we  thought  that  it  had  all  come 
from  a  single  queen  mother.  We  imagined  how  she  had 
made  an  early  start,  digging  a  hole  in  the  ground,  build- 
ing within  it  a  paper  comb  with  five  or  six  cells  around  a 
3 


WASPS,  SOCIAL  AND  SOLITARY 

central  column,  and  layingN  therein  some  neuter  eggs; 
how  she  had  then  spent  a  month  in  attending  carefully 
to  the  beginnings  of  things,  feeding  the  young  larvae  as 
they  hatched,  and  watching  over  them  through  their 
childhood  and  youth;  and  then  how  her  solicitude  was 
rewarded  by  the  filial  devotion  with  which  this  first  set  of 
workers  took  upon  themselves  the  labor  of  excavating, 
building,  and  feeding  the  young,  everything  indeed  except 
the  egg-laying.  These  queens,  surrounded  though  they 
are  by  respectful  and  attentive  subjects,  have  much  the 
worst  of  it  in  our  estimation,  never  going  out,  and  passing 
their  lives  in  a  dull  routine.  Through  the  early  summer 
only  neuters  are  produced,  but  when  fall  approaches  the 
future  generation  is  provided  for  by  the  development  of 
males  and  females.  The  activity  of  the  little  colony  is 
limited  by  the  season,  for  as  the  days  grow  colder  the 
males  and  females  leave  the  nest  and  mate,  and  a  little 
later  both  males  and  workers  lose  ambition,  become 
inactive  and  finally  die,  while  the  queens  hide  away  in 
protected  corners  to  reappear  in  the  spring.  The  eggs 
and  larvae,  left  unfed  and  uncared  for,  become  a  prey  to 
moulds  and  to  hordes  of  insects,  and  thus  the  swarm 
comes  to  an  end. 

We  had  once  made  some  not  very  successful  attempts  to 
find  out  whether  spiders  had  a  sense  of  color;  and  seeing 
4 


COMMUNAL  LIFE 

that  the  conditions  were  much  more  favorable  with  our 
present  subjects,  we  thought  it  would  be  a  good  plan  to 
test  their  knowledge  of  the  spectrum.  Providing  six 
sheets  of  stiff  paper  two  feet  square,  colored  respectively 
red,  blue,  green,  pink,  and  two  shades  of  yellow,  and  cut- 
ting a  circular  hole  four  and  one  half  inches  in  diameter 
in  the  centre  of  each,  we  began  our  experiments  by  pla- 
cing the  red  paper  over  the  nest  so  that  the  entrance  was 
clearly  exposed.  The  outgoing  wasps  dashed  upward 
without  noticing  it,  but  great  was  the  confusion  among 
the  homecomers.  Thrown  out  of  their  reckoning,  they 
clamored  about  us  in  ever  increasing  swarms.  Like 
Homer's  wasps, 

"  All  rise  in  arms  and  with  a  general  cry 
Assert  their  domes  and  buzzing  progeny," 

and  a  crisis  (for  us)  was  approaching,  when  one,  a  pioneer 
of  thought,  determined  to  go  into  the  hole,  which  did  not 
look  like  the  right  hole,  although  it  was  where  the  right 
hole  ought  to  be;  and  so  potent  is  example  that  one  by 
one  the  others  followed.  Three  hours  later  they  had 
become  accustomed  to  the  change,  and  went  in  and  out 
as  usual. 

They  had  noticed  the  paper  ;  that  was  plain  enough, 
but  did  they  notice  the  redness?    To  test  this,  we  left 
things  as  they  were  for  two  days,  and  then  substituted 
5 


WASPS,  SOCIAL  AND   SOLITARY 

blue  paper  for  the  red.  Again  the  confusion,  the  swarm- 
ing of  fervent  legions,  the  noisy  expostulations,  the 
descent  of  one  after  another;  but  this  time  they  settled 
down  to  their  ordinary  routine  in  a  little  more  than  two 
hours.  On  the  following  day  we  removed  the  blue  paper, 
leaving  the  grass  around  the  nest  exposed ;  and  this 
proved  a  new  source  of  mystification,  but  not  so  serious 
as  the  others.  At  the  end  of  an  hour  twenty-five  or  thirty 
were  still  buzzing  about,  needing  the  guidance  of  the 
blue  paper  to  get  inside,  and  entering  at  once  when  it 
was  replaced.  As  we  tried  new  colors  from  day  to  day  a 
few  of  the  wasps  became  entirely  reconciled  to  our  inter- 
ference, and  paid  no  attention  to  the  changes,  while  the 
others  grew  more  or  less  accustomed  to  the  idea  of  muta- 
bility, and  were  but  little  disturbed,  although  they  still 
showed  their  consciousness  of  each  alteration  by  making 
a  few  circles  before  going  in.  We  once  placed  some  dark 
red  nasturtiums  on  light  yellow  paper  near  the  nest,  and 
found  that  more  than  one  third  of  the  homecoming 
wasps  flew  to  them  and  hovered  over  them  before  enter- 
ing. When  light  yellow  nasturtiums,  nearly  matching  the 
paper  in  color,  were  substituted,  only  one  out  of  thirty- 
six  noticed  them;  and  as  the  odor  was  as  strong  in  one 
case  as  the  other,  it  would  seem  that  the  color  was  the 
attracting  force. 

6 


COMMUNAL    LIFE 

Our  final  color  experiment  was  to  let  the  blue  paper 
remain  for  a  day  or  two,  giving  time  for  all  the  wasps  to 
become  familiar  with  it,  and  then  to  leave  it  on  the 
ground  a  foot  and  a  half  away,  while  replacing  it  with 
yellow.  This  gave  a  false  nest  surrounded  by  the  color 
that  they  had  been  associating  with  the  entrance,  and  a 
true  nest  surrounded  by  a  new  color.  In  the  next  ten 
minutes  two  hundred  and  seventy  wasps  came  home,  and 
every  one  of  them  went  to  the  false  nest.  Many  circled 
above  it,  others  entered  the  hole  in  the  paper,  and  some 
began  to  excavate,  and  made  quite  a  depression  in  the 
ground;  but  gradually  they  found  their  way  home. 
Three  hours  later  seventy-six  wasps  entered  the  false 
nest  in  five  minutes,  and  at  evening  they  were  still  visiting 
it  in  goodly  numbers ;  but  on  the  next  day  we  saw  only 
two  that  were  deceived. 

On  successive  days  we  substituted  red  for  yellow, 
green  for  red,  and  so  on,  always  with  similar  results, 
although  the  wasps  became  more  and  more  accustomed 
to  the  vicissitudes  of  their  life,  and  after  a  time  seemed  to 
look  for  the  hole  itself  without  relying  upon  the  color  to 
guide  them.  They  found  their  nest  under  a  color  new  to 
them  much  more  readily  than  when  the  paper  was  taken 
entirely  away  and  the  ground  left  exposed.  Once  when 
the  green  paper  was  around  their  nest,  and  the  wind 
7 


WASPS,    SOCIAL    AND    SOLITARY 

blew  it  over  the  hole  so  that  they  could  not  enter,  at  least 
one  hundred  collected,  many  of  them  settling  in  the  false 
nest;  when  we  lifted  the  green  paper,  leaving  the  hole 
free,  only  three  or  four  entered,  but  when  we  put  it  back 
in  place  they  rushed  in  six  or  seven  at  a  time.  It  was 
plainly  the  color  that  directed  them. 

This  was  a  nearly  rainless  summer,  —  a  condition 
extremely  favorable  to  wasp  development.  Nests  multi- 
plied and  grew  until  the  whole  country-side  complained, 
and  no  wonder,  for  houses  were  full  of  them,  and  at  meal- 
times they  gathered  at  the  table  with  the  members  of  the 
family.  How  did  they  know  when  dinner  was  ready  ? 
It  could  not  have  been  by  the  sight,  unfamiliar  to  them, 
of  cooked  food  ;  was  it,  then,  through  the  sense  of 
smell? 

Many  were  the  questions  that  we  asked  in  vain  of 
our  Vespas,  but  here  was  one  that  they  could  readily 
be  made  to  answer.  We  rolled  up  two  bundles,  one  of 
nothing  but  gauze,  and  another,  like  it  in  appearance, 
but  containing  some  warm  chicken  bones ;  these  were 
laid  to  one  side  of  the  nest,  the  color  of  the  gauze 
matching  that  of  the  paper  on  which  it  was  placed. 
The  wasps  in  returning  to  the  nest,  even  though  loaded 
with  food,  could  not  resist  the  appetizing  odor,  and 
settled  thickly  upon  the  bone  bundle,  trying  their  best 
8 


COMMUNAL    LIFE 

to  penetrate  within,  while  the  empty  gauze  was  un- 
noticed. As  the  bones  grew  cold  and  dry  they  attracted 
less  attention,  but  two  days  later  they  were  occasion- 
ally visited. 

Having  killed  two  wasps  that  had  alighted  on  the 
ground,  by  striking  them  with  a  folded  paper,  we  took 
them  up  and  placed  one  of  them  at  a  distance,  so  that 
it  was  entirely  hidden  in  the  grass.  Five  settled  above 
it,  and  after  they  had  carried  it  away  the  place  was 
visited  by  several  others,  while  the  spot  upon  which  we 
had  killed  them  drew  to  it  nine  wasps  within  fifteen 
minutes.  Thus  they  seemed  very  keen  of  scent  where 
animal  matter  was  concerned ;  but  the  powerful  oils  of 
peppermint  and  wintergreen,  although  noticed,  aroused 
little  attention,  perhaps  because  they  indicated  nothing 
of  interest  to  them. 

Our  experiments  on  hearing  met  with  negative  results. 
The  wasps  seemed  insensible  to  any  noise  we  could 
make  or  that  we  could  produce  by  whistles  of  various 
degrees  of  shrillness.  This  of  course  does  not  show  that 
they  cannot  hear,  and  any  one  who  has  been  unfortunate 
enough  to  disturb  them  in  the  neighborhood  of  their  nest 
will  remember  how  their  angry  buzzing  seemed  to  serve 
as  a  battle  cry  to  gather  all  the  members  of  the  clan  for 
the  attack. 

9 


WASPS,    SOCIAL   AND    SOLITARY 

Our  Vespas  began  to  work  an  hour  or  two  after  sun- 
rise, and  did  not  stop  until  dusk.  One  cloudy  evening 
when  darkness  fell  early  they  continued  to  return  to  the 
nest,  being  able  to  fly  to  the  right  spot  without  any  hesi- 
tation, although  our  vision  did  not  permit  us  to  see  the 
opening  without  going  down  on  our  knees  and  looking 
closely.  At  last  it  grew  perfectly  dark,  and  we  stuffed  a 
handkerchief  into  the  hole,  with  the  result  that  seventy- 
five,  coming  home  without  a  ray  of  light  to  guide  them, 
were  shut  out,  and  were  found  clustered  about  the  spot 
on  the  following  morning. 

We  wanted  to  estimate  the  amount  of  labor  done  by  a 
worker  in  a  day,  and  so,  rising  one  morning  at  the  first 
bird  call,  we  went  out  into  the  freshness  of  dawn,  and  for 
an  hour  had  the  world  to  ourselves ;  but  a  little  before  five 
a  few  straggling  wasps  that  had  stayed  out  all  night 
began  to  bring  in  loads,  and  by  half  past  seven  they  were 
fairly  under  way.  From  half  past  four  until  twelve  we 
counted  all  that  passed,  4534  going  out  and  3362  coming 
home;  and  with  all  this  activity  there  seemed  to  be  no 
pleasure  excursions,  for  each  one  carried  food  when 
returning,  and  took  out  a  pellet  of  earth  when  leaving. 
We  once  raised  a  little  garden  from  the  pellets  that  were 
dropped  on  our  porch  table  where  we  kept  a  bowl  of 
water.  Wasps  are  great  drinkers,  and  when  they  find 


COMMUNAL   LIFE 


such  a  provision  they  come  frequently  to  refresh  them- 
selves, dropping  their  loads  as  they  alight.  This  habit 
of  holding  on  to  their  loads  until  they  settle  down  may 
perhaps  make  them  a  factor  in  extending  the  boundaries 
of  plant  distribution,  both  under  ordinary  conditions 
and  when,  as  must  often  happen  with  little  creatures 
flying  so  high,  they  are  blown  to  long  distances  from 
home. 

Having  kept  close  track  not  only  of  the  numbers,  but  of 
the  hours,  each  count 
being  made  to  cover 
five  minutes,  we  were 
able  to  calculate  that 
an  average  trip  occu- 
pied forty-three  min- 
utes. When  we  met 
these  wasps  in  the 
garden  they  never 
seemed  to  be  hurry- 
ing, and  had  the  air 
of  amusing  them- 
selves; but  they  must 
be  faithful  workers  to 
accomplish  so  much.  The  curious  fact  has  been  estab- 
lished that  when  food  is  very  plentiful  the  workers 


PAPER    NEST    WITH    SIDE    REMOVED   TO 
SHOW   CONSTRUCTION    OF   COMBS 


WASPS,    SOCIAL    AND    SOLITARY 

begin  to  lay  male  eggs,  thus  taking  from  the  queen  a 
part  of  her  burden  and  leaving  her  free  to  produce 
neuters  and  females.  The  nest  that  we  were  watching 
was  found,  at  the  end  of  the  season,  to  contain  4661 
wasps  in  various  stages  of  development,  and  others  that 
we  opened  had  from  two  to  four  thousand.  This  is  no- 
thing to  the  social  wasps  of  China,  where  a  single  house- 
hold is  made  up  of  from  fifteen  to  twenty  thousand  mem- 
bers; but  China  is  a  thickly  populated  country,  and  per- 
haps with  wasps  as  with  human  beings  several  families 
live  in  a  single  domicile. 

Outside  of  their  wonderful  social  instincts  our  wasps 
are  found  wanting  in  the  higher  gifts  of  emotion  and  in- 
tellect. When  we  killed  a  number  of  them  and  placed 
them  near  the  nest,  their  nearest  relatives  wasted  no  time 
in  mourning,  nor  yet  in  revenge,  but  calmly  cut  up  the 
bodies  and  fed  them  to  the  ever  hungry  young  ones.  If 
we  placed  some  rich  and  tempting  morsels  at  a  distance, 
two  or  three  would  discover  them,  and  would  go  back 
and  forth  all  day  without  telling  the  others  about  it,  as 
ants  would  have  done  under  like  circumstances.  When 
we  obstructed  the  opening  to  their  nest  by  lightly  laying 
blades  of  grass  across,  the  day  passed  without  its  occur- 
ring to  the  wasps  to  lift  them  away,  although  they  suf- 
fered the  greatest  inconvenience  in  getting  in  and  out, 

12 


COMMUNAL   LIFE 

crawling  laboriously  through,  and  in  some  instances  giv- 
ing up  the  task  and  flying  away. 

Vespa  maculata,  building  on  trees  and  fences,  has 
practically  the  same  habits  as  the  ground  wasp,  german- 
ica,  the  internal  structure  of  the  nest  following  the  same 
plan,  while  the  outer  wall  is  of  a  papery  substance  like 
that  of  the  combs,  made  from  the  scrapings  of  weather- 
beaten  wood.  The  genus  Polistes  builds  combs  similar 
to  that  of  Vespa,  under  porches  or  in  any  sheltered  place, 
and  does  not  inclose  them.  All  these  wasps,  when  adult, 
enjoy  fruit  and  flowers  as  well  as  animal  food;  but  only 
this  last  is  used  for  the  young,  and  many  a  caterpillar 
creeping  along  with  sinister  design  is  snatched  by  them 
to  be  chewed  into  a  pulpy  mass,  and  then  fed  to  the 
larvae.  No  calculation  has  been  made  of  the  value  of 
these  wasps  in  agriculture,  and  one  of  the  things  that 
farmers  have  yet  to  learn  is  to  encourage  their  presence 
in  orchards  and  gardens. 

Some  species  are  said  to  sting  the  drones  and  larvae  to 
death  at  the  close  of  the  season,  but  this  habit  is  not  fol- 
lowed by  V.  germanica  and  V.  maculata.  Since  there  is 
no  store  of  provision  to  be  economized  through  the  winter 
the  only  object  of  such  conduct  would  be  the  merciful 
one  of  ending  their  sufferings  at  once  instead  of  letting 
them  perish  by  slow  starvation,  and  we  find  no  evidence 


WASPS,    SOCIAL    AND    SOLITARY 

for  such  elevated  ideas.  What  makes  for  the  welfare  of 
the  species  they  thoroughly  attend  to,  but  beyond  that 
point  they  do  not  go. 

The  socialism  of  wasps  is  in  a  less  evolved  state  than 
that  of  bees  and  ants,  and  yet  there  is  in  it  sufficient  sacri- 
fice of  self  to  the  common  good  to  excite  the  respectful 
wonder  of  human  beings,  whose  relations  to  each  other 
and  to  the  state  have  such  different  standards. 


Chapter  II 

AMMOPHILA    AND    HER    CATERPILLARS 

BEFORE  we  had  worked  long  on  our  Vespa  family 
we  were  beguiled  by  tempting  opportunities  into 
running  after  the  solitary  wasps.  The  solitaries,  so  far  as 
species  are  concerned,  are  immensely  more  numerous 
than  the  socials  ;  but  they  have  only  two  sexes,  and  the 
males  and  females  usually  see  but  little  of  each  other 
after  the  mating  is  over,  although  we  occasionally  find 
them  living  happily  together  until  the  end  of  the  season. 
In  the  early  summer  they  begin  to  emerge  from  the  nest 
in  which  the  eggs  were  laid  the  year  before.  Solitary  in- 
deed they  come  into  the  world,  the  generation  that  gave 
them  birth  having  perished  in  the  fall.  For  a  time  their 
career  is  one  of  unmixed  pleasure,  and  yet,  free  and  un- 
guided  though  they  are,  basking  in  the  sunshine,  feeding 
on  the  flowers,  or  sleeping  at  night  under  some  sheltering 
leaf,  they  are  hourly  acquiring  experience,  so  that  when 
the  cares  of  life  descend  upon  them  they  are  no  longer 
creatures  of  mere  instinct.  With  these  sobering  cares  an 
15 


WASPS,    SOCIAL   AND    SOLITARY 

almost  absurdly  heavy  sense  of  responsibility  for  future 
generations  transforms  the  hitherto  happy-go-lucky  fe- 
males into  grown-up  wasps  with  serious  views  on  market- 
ing and  infant  foods.  Each  one  makes  a  separate  nest 
and  provisions  it  by  her  own  labor  ;  and  in  many  cases  a 
new  nest  is  made  for  each  egg.  There  is  no  cooperation 
among  them  ;  although  in  certain  genera,  as  Aphilan- 
thops  and  Bembex,  a  number  of  individuals  build  close 
together,  forming  a  colony.  The  nests  may  be  made  of 
mud,  and  attached  for  shelter  under  leaves,  rocks,  or 
eaves  of  buildings,  or  may  be  burrows  hollowed  out  in 
the  ground,  in  trees  or  in  the  stems  of  plants.  The  adult 
wasp  lives  upon  fruit  or  nectar,  but  the  young  grub  or 
larva  must  have  animal  food ;  and  here  the  parent  wasp 
shows  a  rigid  conservatism,  each  species  providing  the 
sort  of  food  that  has  been  approved  by  its  family  for 
generations,  one  taking  flies,  another  bugs,  and  another 
beetles,  caterpillars,  grasshoppers,  crickets,  locusts, 
spiders,  cockroaches,  aphides,  or  other  creatures,  as  the 
case  may  be. 

When  the  egg-laying  time  arrives  the  female  secures 
her  prey,  which  she  either  kills  or  paralyzes,  places  it  in 
the  nest,  lays  the  egg  upon  it,  and  then,  in  most  cases, 
closes  the  hole  and  takes  no  further  interest  in  it,  going  on 
to  make  new  nests  from  day  to  day.  In  some  genera  the 
16 


AMMOPHILA   AND    HER    CATERPILLARS 

female  maintains  a  longer  connection  with  her  offspring, 
not  bringing  all  the  provision  at  once,  but  returning  to 
feed  the  larva  as  it  grows,  and  leaving  the  nest  perma- 
nently only  when  the  grub  has  spun  its  cocoon.  The 
males  never  acquire  this  interest,  so  admirable  for  the 
development  of  character,  and  aid  little,  if  at  all,  in 
the  care  of  the  family.  The  egg  develops  in  from  one  to 
three  days  into  a  footless,  maggot-like  creature  which 
feeds  upon  the  store  provided  for  it,  increasing  rapidly 
in  size,  and  entering  the  pupal  stage  in  from  three  days 
to  two  weeks.  In  the  cocoon  it  passes  through  its  final 
metamorphosis,  emerging  as  a  perfect  insect,  perhaps  in 
two  or  three  weeks,  or,  in  many  cases,  after  the  winter 
months  have  passed  and  summer  has  come  again. 

Most  graceful  and  attractive  of  all  the  wasps  —  "  taille 
effilee,  tournure  svelte"  as  Fabre  describes  them,  the  Am- 
mophiles,  of  all  the  inhabitants  of  the  garden,  hold  the 
first  place  in  our  affections.  Not  so  beautiful  as  the  blue 
Pelopaeus,  nor  so  industrious  as  the  little  red-girdled  Try- 
poxylon,  their  intelligence,  their  distinct  individuality, 
and  their  obliging  tolerance  of  our  society  make  them 
an  unfailing  source  of  interest.  They  are,  moreover,  the 
most  remarkable  of  all  genera  in  their  stinging  habits, 
being  supposed  to  use  the  nicest  surgical  skill  in  para- 
lyzing their  caterpillars  ;  and  few  things  have  given  us 
17 


WASPS,    SOCIAL   AND    SOLITARY 

deeper  pleasure  than  our  success  in  following  the  ac- 
tivities and  penetrating  the  secrets  of  their  lives.  In  our 
garden  we  have  two  species  of  Ammophila,  urnaria  Cres- 
son,  and  gracilis  Cresson,  both  of  them  being  very  slender- 
bodied  wasps  of  about  an  inch  in  length,  gracilis  all  black, 
and  urnaria  with  a  red  band  around  the  front  end  of  the 
abdomen.  A.  polita  and  A.  vulgaris,  which  look  much 
like  urnaria,  are  common  in  the  sandy  fields  west  and 
south  of  Milwaukee. 

During  the  earlier  part  of  the  summer  we  had  often 
seen  these  wasps  feeding  upon  the  nectar  of  flowers, 
especially  upon  that  of  the  sorrel,  of  which  they  are  par- 
ticularly fond;  but  at  that  time  we  gave  them  but  pass- 
ing notice.  One  bright  morning,  however,  we  came  upon 
an  urnaria  that  was  so  evidently  hunting,  an4  hunting  in 
earnest,  that  we  gave  up  everything^lse  to  follow  her. 
The  ground  was  covered,  more  or  less  thickly,  with 
patches  of  purslain,  and  it  was  under  these  weeds  that  our 
Ammophila  was  eagerly  searching  for  her  prey.  After 
thoroughly  investigating  one  plant  she  would  pass  to  an- 
other, running  three  or  four  steps  and  then  bounding  as 
though  she  were  made  of  thistledown  and  were  too  light  to 
remain  upon  the  ground.  We  followed  her  easily,  and  as 
she  was  in  full  view  nearly  all  of  the  time  we  had  every 
hope  of  witnessing  the  capture;  but  in  this  we  weredes- 
18 


[MOPHILA   AND    HER    CATERPILLARS 

tined  to  disappointment.  We  had  been  in  attendance  on 
her  for  about  a  quarter  of  an  hour  when,  after  disappear- 
ing for  a  few  moments  under  the  thick  purslain  leaves, 
she  came  out  with  a  green  caterpillar.  We  had  missed  the 
wonderful  sight  of  the  paralyzer  at  work;  but  we  had  no 
time  to  bemoan  our  loss,  for  she  was  making  off  at  so 


AMMOPHILA    URNARIA   CARRYING   CATERPILLAR   TO    NEST 

rapid  a  pace  that  we  were  well  occupied  in  keeping  up 
with  her.  She  hurried  along  with  the  same  motion  as 
before,  unembarrassed  by  the  weight  of  her  victim.  For 
sixty  feet  she  kept  to  open  ground,  passing  between  two 
rows  of  bushes;  but  at  the  end  of  this  division  of  the  gar- 
den, she  plunged,  very  much  to  our  dismay,  into  a  field 
19 


WASPS,    SOCIAL   AND    SOLITARY 

of  standing  corn.  Here  we  had  great  difficulty  in  follow- 
ing her,  since,  far  from  keeping  to  her  former  orderly 
course,  she  zigzagged  among  the  plants  in  the  most  be- 
wildering fashion,  although  keeping  a  general  direction 
of  northeast.  It  seemed  quite  impossible  that  she  could 
know  where  she  was  going.  The  corn  rose  to  a  height  of 
six  feet  all  around  us ;  the  ground  was  uniform  in  appear- 
ance, and,  to  our  eyes,  each  group  of  cornstalks  was  just 
like  every  other  group,  and  yet,  without  pause  or  hesita- 
tion, the  little  creature  passed  quickly  along,  as  we  might 
through  the  familiar  streets  of  our  native  town. 

At  last  she  paused  and  laid  her  burden  down.  Ah!  the 
power  that  has  led  her  is  not  a  blind,  mechanically  per- 
fect instinct,  for  she  has  traveled  a  little  too  far.  She 
must  go  back  one  row  into  the  open  space  that  she  has 
already  crossed,  although  not  just  at  this  point.  Nothing 
like  a  nest  is  visible  to  us;  the  surface  of  the  ground  looks 
all  alike,  and  it  is  with  exclamations  of  wonder  tljat  we 
see  our  little  guide  lift  two  pellets  of  earth  which\  have 
served  as  a  covering  to  a  small  opening  running  down 
into  the  ground. 

The  way  being  thus  prepared,  she  hurries  back  with 

her  wings  quivering  and  her  whole  manner  betokening 

*ieyful  triumph  at  the  completion  of  her  task.  We,  in 

the  mean  time,  have  become  as  much  excited  over  the 

20 


AMMOPHILA   AND    HER   CATERPILLARS 

matter  as  she  is  herself.  She  picks  up  the  caterpillar, 
brings  it  to  the  mouth  of  the  burrow,  and  lays  it  down. 
Then,  backing  in  herself,  she  catches  it  in  her  mandi- 
bles and  drags  it  out  of  sight,  leaving  us  full  of  admira- 
tion and  delight. 

How  clear  and  accurate  must  be  the  observing  powers 
of  these  wonderful  little  creatures !  Every  patch  of  ground 
must,  for  them,  have  its  own  character  ;  a  pebble  here, 
a  larger  stone  there,  a  trifling  tuft  of  grass  —  these  must 
be  their  landmarks.  And  the  wonder  of  it  is  that  their 
interest  in  each  nest  is  so  temporary.  A  burrow  is  dug, 
provisioned  and  closed  up,  all  in  two  or  three  days,  and 
then  another  is  made  in  a  new  place  with  everything  to 
learn  over  again. 

From  this  time  on  to  the  first  of  September  our  garden 
was  full  of  these  wasps,  and  they  never  lost  their  fasci- 
nation for  us ;  although,  owing  to  a  decided  difference  be- 
tween their  taste  and  ours  as  to  what  constituted  pleasant 
weather,  all  our  knowledge  of  them  was  gained  by  the 
sweat  of  our  brows.  When  we  wished  to  utilize  the  cool 
hours  of  the  morning  or  of  the  late  afternoon  in  studying 
them,  or  thought  to  take  advantage  of  a  cloud  which  cast 
a  grateful  shade  over  the  sun  at  noonday,  where  were 
our  Ammophiles  ?  Out  of  sight  entirely,  or  at  best  only* 
to  be  seen  idling  about  on  the  flowers  of  the  onion  or 
21 


WASPS,    SOCIAL   AND    SOLITARY 

sorrel.  At  such  a  time  they  seemed  to  have  no  mission 
in  life  and  no  idea  of  duty.  But  when  the  air  was  clear 
and  bright  and  the  mercury  rose  higher  and  higher,  all 
was  changed.  Their  favorite  working  hours  were  from 
eleven  in  the  morning  to  three  in  the  afternoon,  and 
when  they  did  work  they  threw  their  whole  souls  into  it. 
It  was  well  that  it  was  so,  for  they  certainly  needed  all 
the  enthusiasm  and  perseverance  that  they  could  muster 
for  such  wearisome  and  disappointing  labor.  Hour  after 
hour  was  passed  in  search,  and  often  there  was  nothing 
to  show  at  the  end  of  it.  Urnaria  hunted  on  bare  ground, 
on  the  purslain,  and  most  of  all  on  the  bean-plants. 
These  were  examined  carefully,  the  wasp  going  up  and 
down  the  stems  and  looking  under  every  leaf ;  but  the 
search  was  so  frequently  unsuccessful  that  in  estimating 
their  work  we  are  inclined  to  think  that  they  can  scarcely 
average  one  caterpillar  a  day. 

In  this  species,  as  in  every  one  that  we  have  studied, 
we  have  found  a  most  interesting  variation  among  the 
different  individuals,  not  only  in  methods,  but  in  char- 
acter and  intellect.  While  one  was  beguiled  from  her 
hunting  by  every  sorrel  blossom  she  passed,  another 
stuck  to  her  work  with  indefatigable  perseverance.  While 
one  stung  her  caterpillar  so  carelessly  and  made  her  nest 
in  so  shiftless  a  way  that  her  young  could  survive  only 

22 


AMMOPHILA   AND    HER    CATERPILLARS 

through  some  lucky  chance,  another  devoted  herself  to 
these  duties  not  only  with  conscientious  thoroughness, 
but  with  an  apparent  craving  after  artistic  perfection 
that  was  touching  to  see. 

The  method  employed  by  the  Ammophiles  in  stinging 
their  prey  is  more  complex  than  that  of  any  other  preda- 
tory wasp.  The  larvae  with  which  they  provision  their 
nests  are  made  up  of  thirteen  segments,  and  each  of 
these  has  its  own  nervous  centre  or  ganglion.  Hence  if 
the  caterpillar  is  to  be  reduced  to  a  state  of  immobility, 
or  to  a  state  so  nearly  approaching  immobility  that  the 
egg  may  be  safely  laid  upon  it,  a  single  sting,  such  as 
is  given  by  some  of  the  Pompilidas  to  their  captured 
spiders,  will  be  scarcely  sufficient.  All  this  we  knew  from 
Fabre's  "Souvenirs,"  and  yet  we  were  not  at  all  pre- 
pared to  believe  that  any  plain  American  wasp  could 
supply  us  with  such  a  thrilling  performance  as  that  of 
the  Gallic  hirsuta,  which  he  so  dramatically  describes. 
We  were,  however,  most  anxious  to  be  present  at  the  all- 
important  moment  that  we  might  see  for  ourselves  just 
how  and  where  urnaria  stings  her  victim. 

For  a  whole  week  of  scorching  summer  weather  we 

lived  in  the  bean  patch,  scorning  fatigue.  We  quoted  to 

each  other  the  example  of  Fabre's  daughter  Claire,  who 

followed  Odynerus  with  unfaltering  zeal  until  a  sun- 

23 


WASPS,    SOCIAL    AND    SOLITARY 

stroke  laid  her  low.  We  attended  scores  of  wasps  as  they 
hunted;  we  ran,  we  threw  ourselves  upon  the  ground, 
we  scrambled  along  on  our  hands  and  knees  in  our  des- 
perate endeavors  to  keep  them  in  view,  sometimes  with 
our  eyes  upon  the  wasps  themselves  and  sometimes  pur- 
suing their  shadows,  which,  like  those  of  coming  events, 
were  cast  before  ;  and  yet  they  escaped  us.  After  we  had 
kept  one  in  sight  for  an  hour  or  more,  some  sudden  flight 
would  carry  her  far  away,  and  all  our  labor  was  lost. 

At  last,  however,  our  day  came.  We  were  doing  a 
little  hunting  on  our  own  account,  hoping  to  find  some 
larvae  which  we  could  drop  in  view  of  the  wasps  and  thus 
lead  them  to  display  their  powers,  when  we  saw  an 
urnaria  fly  up  from  the  ground  to  the  underside  of  a 
bean  leaf  and  knock  down  a  small  green  caterpillar. 
Breathless  with  an  excitement  which  will  be  understood 
by  those  who  have  tasted  the  joy  of  such  a  moment,  we 
hung  over  the  actors  in  our  little  drama.  The  ground 
was  bare,  we  were  close  by  and  could  see  every  motion 
distinctly.  Nothing  more  perfect  could  have  been 
desired. 

The  wasp  attacked  at  once,  but  was  rudely  repulsed, 

the  caterpillar  rolling  and  unrolling  itself  rapidly  and 

with  the  most  violent  contortions  of  the  whole  body. 

Again  and  again  its  adversary  descended,  but  failed  to 

24 


AMMOPHILA   AND   HER   CATERPILLARS 

gain  a  hold.  The  caterpillar,  in  its  struggles,  flung  itself 
here  and  there  over  the  ground,  and  had  there  been  any 
grass  or  other  covering  near  by  it  might  have  reached  a 
place  of  partial  safety ;  but  there  was  no  shelter  within 
reach,  and  at  the  fifth  attack  the  wasp  succeeded  in 
alighting  over  it,  near  the  anterior  end,  and  in  grasping 
its  body  firmly  in  her  mandibles.  Standing  high  on  her 
long  legs  and  disregarding  the  continued  struggles  of  her 
victim,  she  lifted  it  from  the  ground,  curved  the  end  of 
her  abdomen  under  its  body,  and  darted  her  sting  be- 
tween the  third  and  fourth  segments.  From  this  instant 
there  was  a  complete  cessation  of  movement  on  the  part 
of  the  unfortunate  caterpillar.  Limp  and  helpless,  it 
could  offer  no  further  opposition  to  the  will  of  its  con- 
queror. For  some  moments  the  wasp  remained  motion- 
less, and  then,  withdrawing  her  sting,  she  plunged  it 
successively  between  the  third  and  the  second,  and 
between  the  second  and  the  first  segments. 

The  caterpillar  was  now  left  lying  on  the  ground.  For 
a  moment  the  wasp  circled  above  it,  and  then,  descend- 
ing, seized  it  again,  further  back  this  time,  and  with 
great  deliberation  and  nicety  of  action  gave  it  four  more 
stings,  beginning  between  the  ninth  and  tenth  segments 
and  progressing  backward. 

Urnaria,  probably  feeling  —  as  we  certainly  did  —  a 
25 


WASPS,   SOCIAL   AND    SOLITARY 

reaction  from  the  strain  of  the  last  few  minutes,  and  a 
relief  at  the  completion  of  her  task,  now  rested  from  her 
labors.  Alighting  on  the  ground  close  by,  she  proceeded 
to  smooth  her  body  with  her  long  hind  legs,  standing,  in 
the  mean  time,  almost  on  her  head,  with  her  abdomen 
directed  upward.  She  then  gave  her  face  a  thorough 
washing  and  rubbing  with  her  first  legs,  and  not  until 
she  had  made  a  complete  and  satisfactory  toilet  did  she 
return  to  the  caterpillar. 

We  saw  Ammophila  capture  her  prey  only  three  times 
during  the  whole  summer;  but  from  these  observations 
and  from  the  condition  of  her  caterpillars  taken  at  vari- 
ous times  from  nests,  her  method  seems  to  be  wonder- 
fully close  to  that  of  hirsuta,  with  just  about  the  same 
amount  of  variation  in  different  individuals. 

Thus  in  our  second  example,  she  stung  the  first  three 
segments  in  the  regular  order,  the  third,  the  second,  and 
lastly  (and  most  persistently)  the  first.  She  then  went  on, 
without  a  pause,  to  sting  the  fourth,  fifth,  sixth,  and 
seventh,  stopping  at  this  point  and  leaving  the  posterior 
segments  untouched.  In  our  first  example,  it  will  be 
remembered,  the  middle  segments  were  spared.  The 
stinging  being  completed,  she  proceeded  to  the  process 
known  as  malaxation,  which  consists  in  repeatedly 
squeezing  the  neck  of  the  caterpillar,  or  other  victim, 
26 


AMMOPHILA   AND    HER    CATERPILLARS 


between  the  mandibles,  the  subject  of  the  treatment 
being  turned  around  and  around  so  that  all  sides  may  be 
equally  affected. 

In  our  third  case  a  caterpillar  which  we  had  caught 
was  placed  in  front  of  a  wasp  just  after  she  had  carried 
the  second  larva  into  her  nest.  She  seemed  rather  indif- 
ferent to  it,  passing  it  once  or  twice  as  she  ran  about,  but 
finally  picked  it  up  and  gave  it  one  prolonged  sting  be- 
tween the  third  and  fourth  segments.  She  then  spent  a 


AMMOPHILA   URNARIA    STINGING   CATERPILLAR 

long  time  in  squeezing  the  neck,  pinching  it  again  and 
again,  after  which  it  was  left  on  the  ground;  and  as  she 
showed  no  further  interest  in  it  we  carried  it  home  for 
further  study. 

27 


WASPS,    SOCIAL   AND    SOLITARY 

In  the  three  captures,  then,  that  came  under  our  ob- 
servation, all  the  caterpillars  being  of  the  same  species 
and  almost  exactly  of  the  same  size,  three  different 
methods  were  employed.  In  the  first,  seven  stings  were 
given  at  the  extremities,  the  middle  segments  being  left 
untouched,  and  no  malaxation  was  practiced.  In  the 
second,  seven  stings  again,  but  given  in  the  anterior  and 
middle  segments,  followed  by  slight  malaxation.  In  the 
third,  only  one  sting  was  given,  but  the  malaxation  was 
prolonged  and  severe. 

Let  us  now  compare  these  variations  with  those  of 
Fabre.  In  his  first  case  the  sting  entered  at  twelve  dif- 
ferent points,  beginning  between  the  first  and  second 
segments  and  progressing  regularly  backward.  There 
was  no  malaxation.  In  his  second  example  the  third, 
second,  and  first  segments  were  stung  in  the  order  given, 
and  thereafter  each  succeeding  segment  up  to  the  ninth, 
nine  stings  being  given  in  all,  with  careful  malaxation 
following.  In  his  later  experiments,  which  seem  to  have 
been  numerous,  he  found  that  as  a  usual  thing  all  the 
segments  were  stung,  although  the  posterior  three  or 
four  were  occasionally  spared,  but  that  the  order  in 
which  they  were  operated  upon,  as  well  as  the  amount 
of  malaxation,  was  very  variable. 

Our  conclusions,  then,  as  to  Ammophila's  methods  of 
28 


AMMOPHILA   AND    HER    CATERPILLARS 

stinging  agree  fairly  well  with  those  of  Fabre ;  but  there 
is  one  important  exception.  In  his  cases  the  middle  seg- 
ments, upon  one  of  which  the  egg  is  laid  in  our  species 
as  well  as  in  his,  were  in- 
variably stung,  and  this  he 
considers  a  point  of  extreme 
importance.  In  one  of  our 
cases  the  middle  segments 

were  not  touched.  CATERPILLAR  WITH   EGG  OF 

AMMOPHILA   URNARIA 

The  point  in  which  our 

observations  differ  most  widely  from  those  of  Fabre  is 
in  the  condition  of  the  caterpillars  after  the  stinging. 
He  seems  to  have  found  that  they  always  lived  a  long 
time,  but  in  a  motionless  or  nearly  motionless  state ; 
and  he  dwells  at  length  upon  the  necessity  of  both  of 
these  conditions,  since  he  believes  that  while  the  wasp 
larva  must  have  perfectly  fresh  food,  any  violent  mo- 
tion would  imperil  its  safety.  As  a  matter  of  fact  we 
found  a  wide  variation  in  the  thoroughness  with  which 
the  wasps  performed  their  task.  We  had,  in  all,  fifteen 
caterpillars  upon  which  urnaria  had  worked  her  will ; 
and  while  a  few  of  them  fulfilled  to  a  nkety  the  con- 
ditions which  Fabre  believes  to  be  imperative,  most  of 
them  were  far  from  doing  so.  Some  of  them  lived  only 
three  days,  others  a  little  longer,  while  still  others  showed 
29 


WASPS,    SOCIAL   AND    SOLITARY 

signs  of  life  at  the  end  of  two  weeks.  Urnaria  stores 
two  caterpillars,  and  in  more  than  one  instance  the 
second  one  died  and  became  discolored  before  the  first 
one  was  entirely  eaten.  The  wasp  larva  did  not,  as 
might  have  been  expected,  find  fault  with  this  arrange- 
ment, but  proceeded  to  attack  number  two  with  good 
appetite,  ate  it  all  up,  and  then  spun  its  cocoon  as 
though  nothing  unpleasant  had  occurred. 

The  second  condition  was  also  violated.  In  one  case 
the  bite  of  the  newly  hatched  larva  caused  the  caterpillar 
to  rear  upon  end  in  so  violent  a  manner  that  it  looked  as 
though  the  little  creature  would  surely  be  dislodged. 
Another  caterpillar  kept  up  a  continuous  wriggling  with- 
out any  external  stimulation,  and  when  it  was  touched  it 
rolled  about  almost  as  these  larvae  do  in  a  healthy  state, 
and  yet  the  egg  was  not  shaken  off.  The  caterpillar 
which  received  but  a  single  sting,  although  not  motion- 
less, would  have  been  a  safer  repository  for  the  egg  than 
either  of  these.  Others  fulfilled  Fabre's  condition  per- 
fectly, lying  immovable  except  when  stimulated,  and  then 
responding  only  by  a  slight  quivering  of  the  legs  or  skin. 

Among  the  fifteen  caterpillars  that  we  have  taken 
from  the  nests  of  urnaria  three  kinds  are  represented, 
twelve  of  them  belonging  to  one  species,  two  to  the  sec- 
ond, and  one  to  the  third. 

3° 


AMMOPHILA   AND    HER   CATERPILLARS 

The  egg,  which  is  laid  upon  the  side  of  the  sixth  or 
seventh  segment,  hatches  in  from  two  to  three  days;  the 
larva  spends  from  six  days  to  two  weeks  in  eating,  and 
then  spins  its  pale  yellowish  cocoon. 
•  The  nesting  habits  of  urnaria  closely  resemble  those 
of  the  other  members  of  the  genus,  as  reported  by  vari- 
ous observers.  The  spot  chosen  is  in  firm  soil,  sometimes 
in  open  ground,  but  much  more  frequently  under  the 
leaves  of  some  plant.  The  plan  is  a  very  simple  one. 


NEST   OF   AMMOPHILA 


A  tunnel  of  about  an  inch  in  length  leads  to  the  pocket 
in  which  the  caterpillars  are  stored.  There  is  no  harden- 
ing of  the  walls  in  any  part.  We  took  pains  to  draw 
every  nest  that  we  opened,  and  there  was  a  very  con- 
siderable variation  in  the  minor  details,  such  as  the  ob- 
liquity of  the  entrance  tunnel,  the  shape  of  the  pocket, 


WASPS,    SOCIAL   AND    SOLITARY 

and  the  angle  at  which  the  tunnel  and  pocket  were 
joined. 

The  work  is  done  with  the  mandibles  and  the  first 
legs.  When  it  has  proceeded  so  far  that  the  wasp  is  partly 
hidden,  she  begins  to  carry  the  earth  away  from  the  nest.- 
In  doing  this  she  backs  up  to  the  edge  of  the  opening  and, 
flying  a  little  way,  gives  a  sort  of  flirt  which  throws  the 
pellet  that  she  carries  in  her  mandibles  to  a  distance. 
She  then  alights  where  she  is  and  pauses  a  moment  be- 
fore she  runs  back  to  the  hole,  or,  in  some  cases,  darts 
back  on  the  wing.  We  watched  the  process  of  nest-mak- 
ing five  times  during  the  summer.  In  the  first  instance 
Ammophila,  having  made  her  excavation,  ran  off  and 
after  some  search  returned  with  a  good-sized  lump  of 
earth.  This  she  laid  over  the  opening,  which  was  now 
entirely  hidden.  She  then  flew  to  the  bean  patch  close 
by,  but  after  ten  minutes  she  came  back  and  looked  at 
her  nest.  It  was  so  neatly  covered  as  to  be  almost  indis- 
tinguishable, but  to  this  fastidious  little  creature  some- 
thing seemed  lacking.  She  pulled  away  the  cover,  car- 
ried out  three  or  four  more  loads,  and  then  began  to 
search  for  another  piece  for  closing.  After  a  time  she 
came  hurrying  back  with  a  lump  of  earth,  but  when 
close  to  the  nest  she  concluded  that  it  would  not  do, 
dropped  it,  and  ran  off  in  another  direction.  Presently 
32 


AMMOPHILA   AND    HER    CATERPILLARS 

she  found  one  which  fitted  into  the  hole  exactly,  and 
after  placing  it  she  brought  a  much  smaller  piece  which 
she  put  above  and  to  one  side.  She  then  stood  back 
and  surveyed  the  whole,  and  it  seemed  to  us  that  we 
could  read  pride  and  satisfaction  in  her  mien.  She  then 
flew  away,  and  we  supposed  that  that  stage  of  the  work 
was  completed.  Upon  coming  back  two  hours  later, 
however,  we  found  that  she  had  been  trying  some  more 
improvements,  as  a  number  of  little  pellets  had  been 
piled  up  over  the  nest.  This  wasp,  by  the  way,  never 
succeeded  in  finding  a  caterpillar,  since  when  we  opened 
the  burrow  a  few  days  later  it  was  still  empty.  Perhaps 
she  came  to  some  untimely  end. 

Of  the  other  wasps  that  we  saw  making  a  temporary 
closure  of  their  nests,  one  wedged  a  good-sized  stone 
deep  down  into  the  neck  of  the  burrow  and  then  filled 
the  space  above,  solidly,  with  smaller  stones  and  earth. 
Another  placed  two  lumps  of  earth  just  below  the  sur- 
face of  the  ground,  filled  the  opening  with  pellets  loosely 
thrown  in,  and  then  kicked  some  light  dust  over"  the 
whole.  The  others  used  only  two  or  three  lumps  of  earth, 
which  they  fitted  neatly  into  the  opening  just  below  the 
surface.  Although  it  is  usual  for  urnaria  to  leave  her 
nest  closed  while  she  is  off  searching  for  her  prey,  there 
is  no  invariable  rule  in  the  matter,  even  for  single  individ- 
33 


WASPS,    SOCIAL    AND    SOLITARY 

uals.  Once  having  seen  a  wasp  dig  her  nest  and  close  it 
up,  we  drew  some  radiating  lines  from  the  spot,  in  the 
light  dust  that  covered  the  place,  that  we  might  find  it 
again.  When  we  returned,  two  hours  later,  the  same 
wasp  had  made  a  nest  four  or  five  inches  distant  from  the 
first  one,  and  had  left  it  wide  open,  while  she  had  gone 
off  to  search  for  her  caterpillar.  She  had  probably  been 
alarmed  by  the  marks  that  we  had  made,  and  had  felt 
it  necessary  to  dig  a  new  nest,  but  being  in  a  hurry  to 
lay  her  egg  had  omitted  the  usual  process  of  closing  it. 
We  witnessed  the  storing  of  the  caterpillar  and  the  final 
closing. 

From  Fabre  we  learn  that  argentata  and  sabulosa 
close  the  nest  as  soon  as  it  has  been  made,  at  least  when 
the  provisioning  is  to  be  postponed  until  the  next  day, 
while  holosericea  leaves  it  open  until  it  is  completely 
stored.  He  suggests  an  explanation  for  this  variation 
by  dwelling  upon  the  inconvenience  that  would  result  if 
it  were  opened  every  time  that  the  wasp  brought  in  a 
caterpillar,  since  holosericea  stores  up  five  or  six  small 
larvae  instead  of  one  or  two  large  ones.  But  what,  then, 
shall  be  said  of  polita  and  yarrowii,  which,  while  they 
also  store  a  number  of  small  caterpillars,  take  pains  to 
close  and  conceal  the  entrance  every  time  they  come 
out  ?  We  see  the  same  habit  in  other  genera  where  the 
34 


AMMOPHILA   AND    HER    CATERPILLARS 

mother  continually  passes  in  and  out,  as  in  Bembex 
and  Oxybelus. 

Fabre  thinks  that  hirsuta  has  the  habit,  unusual  for 
Ammophila,  of  catching  her  prey  first  and  then  digging 
the  hole  in  which  she  bestows  it.  As  she  takes  only  one 
large  caterpillar  she  is  thus  relieved  of  the  necessity  of 
closing  the  nest  more  than  once. 

As  has  been  said,  urnaria  usually  hunts  a  long  time 
before  she  finds  her  caterpillar,  and  one  or  two  days 
may  pass  before  anything  is  put  into  the  nest.  During 
this  prolonged  search  she  often  revisits  the  spot,  and 
thus  keeps  fresh  the  memory  of  its  locality.  As  soon  as 
the  first  caterpillar  is  stored  she  lays  an  egg  on  it,  and 
then  closes  the  nest  as  before.  The  second  one  may  be 
brought  in  within  a  few  hours  ;  but  in  one  instance  that 
came  under  our  notice  we  feel  sure  that  the  interval 
was  as  much  as  three  days.  We  saw  the  interment  of  the 
second  caterpillar,  and  upon  excavating,  found  on  the 
first  one  a  larva  at  least  a  day  old;  we  suppose  that  at 
least  two  days  had  elapsed  between  the  laying  and  the 
hatching  of  the  egg. 

When  the  provisioning  is  completed  the  time  arrives 
for  the  final  closing  of  the  nest ;  and  in  this,  as  in  all  the 
processes  of  Ammophila,  the  character  of  the  work  dif- 
fers with  the  individual.  For  example,  of  two  wasps  that 
35 


WASPS,    SOCIAL   AND    SOLITARY 

we  saw  close  their  nests  on  the  same  day,  one  wedged 
two  or  three  pellets  into  the  top  of  the  hole,  kicked  in  a 
little  dust,  and  then  smoothed  the  surface  over,  finishing 
it  all  within  five  minutes.  This  one  seemed  possessed 
by  a  spirit  of  hurry  and  bustle,  and  did  not  believe  in 
spending  time  on  non-essentials.  The  other,  on  the  con- 
trary, was  an  artist,  an  idealist.  She  worked  for  an  hour, 
first  filling  the  neck  of  the  burrow  with  fine  earth  which 
was  jammed  down  with  much  energy,  —  this  part  of  the 
work  being  accompanied  by  a  loud  and  cheerful  hum- 
ming, —  and  next  arranging  the  surface  of  the  ground 
with  scrupulous  care,  and  sweeping  every  particle  of 
dust  to  a  distance.  Even  then  she  was  not  satisfied,  but 
went  scampering  around,  hunting  for  some  fitting  object 
to  crown  the  whole.  First  she  tried  to  drag  a  withered 
leaf  to  the  spot,  but  the  long  stem  stuck  in  the  ground 
and  embarrassed  her.  Relinquishing  this,  she  ran  along 
a  branch  of  the  plant  under  which  she  was  working  and, 
leaning  over,  picked  up  from  the  ground  below  a  good- 
sized  stone  ;  but  the  effort  was  too  much  for  her,  and  she 
turned  a  somersault  on  to  the  ground.  She  then  started 
to  bring  a  large  lump  of  earth ;  but  this  evidently  did  not 
come  up  to  her  ideal,  for  she  dropped  it  after  a  moment, 
and  seizing  another  dry  leaf  carried  it  successfully  to 
the  spot  and  placed  it  directly  over  the  nest.  A  third 
36 


AMMOPHILA   AND    HER   CATERPILLARS 

instance  of  the  final  closing  of  the  nest  was  interme- 
diate between  these  two,  the  work  occupying  twenty 
minutes.  The  wasp  first  put  a  plug  well  down,  then 
dropped  in  several  large  pellets,  brushed  in  a  quantity 
of  fine  earth,  and  finally  smoothed  the  surface  over. 

We  had  another  much  less  worthy  example,  one,  in- 
deed, that  went  to  the  extreme  of  carelessness.  We  first 
saw  her  in  the  morning  carrying  her  caterpillar  across 
the  field.  She  frequently  dropped  it  and  ran  or  flew  to  a 
little  distance,  and  when  she  took  it  again  the  venter 
was  sometimes  up  and  sometimes  down,  whichever 
way  it  happened.  Her  nest  was  a  very  poor  affair  just 
beneath  the  surface,  and  after  the  caterpillar  was  carried 
in,  it  was  visible  from  above.  She  filled  the  hole  with 
loose  particles  of  earth  and  then  scratched  the  surface 
of  the  ground  a  little  in  a  perfunctory  sort  of  way,  as 
different  as  possible  from  the  painstaking  labor  that 
we  had  been  accustomed  to  in  her  sisters.  That  afternoon 
we  opened  the  nest  and  removed  its  contents.  The  next 
morning  we  saw  this  wasp  bringing  home  her  second 
caterpillar.  She  was  much  puzzled  and  disturbed  at  the 
destruction  of  her  nest,  and  hunted  for  it  for  an  hour 
and  a  half,  leaving  the  caterpillar  on  the  ground  near 
by.  We  could  not  help  feeling  sorry  that  we  had  inter- 
rupted the  contented  routine  of  her  life.  She  finally  gave 
37 


WASPS,    SOCIAL    AND    SOLITARY 

up  in  despair,  and  we  took  possession  of  the  deserted 
caterpillar. 

Just  here  must  be  told  the  story  of  one  little  wasp 
whose  individuality  stands  out  in  our  minds  more  dis- 
tinctly than  that  of  any  of  the  others.  We  remember 
her  as  the  most  fastidious  and  perfect  little  worker  of 
the  whole  season,  so  nice  was  she  in  her  adaptation  of 
means  to  ends,  so  busy  and  contented  in  her  labor  of 
love,  and  so  pretty  in  her  pride  over  the  completed  work. 
In  filling  up  her  nest  she  put  her  head  down  into  it  and 
bit  away  the  loose  earth  from  the  sides,  letting  it  fall  to 
the  bottom  of  the  burrow,  and  then,  after  a  quantity 
had  accumulated,  jammed  it  down  with  her  head.  Earth 
was  then  brought  from  the  outside  and  pressed  in,  and 
then  more  was  bitten  from  the  sides.  When,  at  last,  the 
filling  was  level  with  the  ground,  she  brought  a  quantity 
of  fine  grains  of  dirt  to  the  spot,  and  picking  up  a  small 
pebble  in  her  mandibles,  used  as  it  a  hammer  in  pound- 
ing them  down  with  rapid  strokes,  thus  making  this 
spot  as  hard  and  firm  as  the  surrounding  surface.  Be- 
fore we  could  recover  from  our  astonishment  at  this 
performance  she  had  dropped  her  stone  and  was  bring- 
ing more  earth.  We  then  threw  ourselves  down  on  the 
ground  that  not  a  motion  might  be  lost,  and  in  a  mo- 
ment we  saw  her  pick  up  the  pebble  and  again  pound 
38 


AMMOPHILA   AND    HER    CATERPILLARS 

the  earth  into  place  with  it,  hammering  now  here  and 
now  there  until  all  was  level.  Once  more  the  whole  pro- 
cess was  repeated,  and  then  the  little  creature,  all  un- 
conscious of  the  commotion  that  she  had  aroused  in 


AMMOPHILA    URNARIA    USING   STONE   TO    POUND   DOWN    EARTH 
OVER    NEST 

our  minds,  —  unconscious,  indeed,  of  our  very  existence 
and  intent  only  on  doing  her  work  and  doing  it  well,  — 
gave  one  final,  comprehensive  glance  around  and  flew 
away. 

We  are  claiming  a  great  deal  for  Ammophila  when  we 
say  that  she  improvised  a  tool  and  made  intelligent  use 
39 


WASPS,    SOCIAL   AND    SOLITARY 

of  it,  for  such  actions  are  rare  even  among  the  higher 
animals;  but  fortunately  our  observation  does  not  stand 
alone,  although  we  supposed  this  to  be  the  case  at  the 
time  that  it  was  made.  Some  weeks  later,  seeing  a  note 
of  a  similar  occurrence  by  Dr.  S.  W.  Williston,  of  Kansas 
University,  we  wrote  to  him  on  the  subject.  In  his  reply 
he  said  that  he  had  waited  for  a  year  before  venturing 
to  publish  his  observation,  fearing  that  so  remarkable  a 
statement  would  not  be  credited.  His  account  is  so  in- 
teresting that  we  quote  it  at  length. 

Even  the  casual  observer,  to  whom  all  insects  are  bugs, 
cannot  help  but  be  struck  by  the  great  diversity  and 
number  of  the  fossorial  Hymenoptera  of  the  plains.  Water 
is  often  inaccessible,  trees  there  are  few  or  none,  and  only 
in  places  is  the  vegetation  at  all  abundant.  A  much  larger 
proportion  of  insects,  hence,  find  it  necessary  to  live  or 
breed  in  holes  in  the  ground,  than  is  the  case  in  more 
favored  localities.  Especially  is  this  the  case  with  the 
Hymenoptera,  great  numbers  and  many  species  of  which 
thus  breed  in  excavations  made  by  themselves. 

While  packing  specimens  on  an  open  space,  uncovered 
by  buffalo  grass,  in  the  extreme  western  part  of  Kansas, 
the  early  part  of  last  July,  the  attention  of  a  friend  and 
myself  was  attracted  by  the  numerous  wasps  that  were 
constantly  alighting  upon  the  ground.  The  hard,  smooth 
baked  surface  showed  no  indications  of  disturbance,  and 
it  was  not  till  we  had  attentively  watched  the  insects  that 
40  ' 


AMMOPHILA   AND    HER    CATERPILLARS 

we  learned  what  they  were  doing.  The  wasp  is  a  very 
slender  one,  more  than  an  inch  in  length,  with  a  slender, 
pedicellate  abdomen ;  it  is  known  to  entomologists  as 
Ammophila  yarrowii  Cres.  They  were  so  numerous  that 
one  was  distracted  by  their  very  multiplicity,  but,  by 
singling  out  different  individuals,  we  were  enabled  to  verify 
each  detail  of  their  operations.  An  insect,  alighting,  ran 
about  on  the  smooth,  hard  surface  till  it  had  found  a  suit- 
able spot  to  begin  its  excavation,  which  was  made  about  a 
quarter  of  an  inch  in  diameter,  nearly  vertical,  and  carried 
to  a  depth  of  about  four  inches,  as  was  shown  by  opening 
a  number  of  them.  The  earth,  as  removed,  was  formed 
into  a  rounded  pellet  and  carefully  carried  to  the  neighbor- 
ing grass  and  dropped.  For  the  first  half  of  an  inch  or  so 
the  hole  was  made  of  a  slightly  greater  diameter.  When 
the  excavation  had  been  carried  to  the  required  depth,  the 
wasp,  after  a  survey  of  the  premises,  flying  away,  soon 
returned  with  a  large  pebble  in  its  mandibles,  which  it 
carefully  deposited  within  the  opening;  then,  standing 
over  the  entrance  upon  her  four  posterior  feet,  she  (I  say 
she,  for  it  was  evident  that  they  were  all  females)  rapidly 
and  most  amusingly  scraped  the  dust  with  her  two  front 
feet,  "hand  over  hand,"  back  beneath  her,  till  she  had 
filled  the  hole  above  the  stone  to  the  top.  The  operation 
so  far  was  remarkable  enough,  but  the  next  procedure  was 
more  so.  When  she  had  heaped  up  the  dirt  to  her  satis- 
faction, she  again  flew  away  and  immediately  returned 
with  a  smaller  pebble,  perhaps  an  eighth  of  an  inch  in 
diameter,  and  then  standing  more  nearly  erect,  with  the 
41 


WASPS,    SOCIAL    AND    SOLITARY 

front  feet  folded  beneath  her,  she  pressed  down  the  dust 
all  over  and  about  the  opening,  smoothing  off  the  surface, 
and  accompanying  the  action  with  a  peculiar  rasping 
sound.  After  all  this  was  done,  and  she  spent  several 
minutes  each  time  in  thus  stamping  the  earth  so  that  only 
a  keen  eye  could  detect  any  abrasion  of  the  surface,  she 
laid  aside  the  little  pebble  and  flew  away  to  be  gone  some 
minutes.  Soon,  however,  she  comes  back  with  a  heavy 
flight,  scarcely  able  to  sustain  the  soft  green  larva,  as  long 
as  herself,  that  she  brings.  The  larva  is  laid  upon  the 
ground,  a  little  to  one  side,  when,  going  to  the  spot  where 
she  had  industriously  labored,  by  a  few,  rapid  strokes  she 
throws  out  the  dust  and  withdraws  the  stone  cover,  laying 
it  aside.  Next,  the  larva. is  dragged  down  the  hole,  where 
the  wasp  remains  for  a  few  minutes,  afterwards  returning 
and  closing  up  the  entrance  precisely  as  before.  This,  we 
thought,  was  the  end,  and  supposed  that  the  wasp  would 
now  be  off  about  her  other  affairs,  but  not  so ;  soon  she 
returns  with  another  larva,  precisely  like  the  first,  and  the 
whole  operation  is  again  repeated.  And  not  only  the 
second  time,  but  again  and  again,  till  four  or  five  of  the 
larvas  have  been  stored  up  for  the  sustainment  of  her  future 
offspring.  Once,  while  a  wasp  had  gone  down  the  hole 
with  a  larva,  my  friend  quietly  removed  tbe  door  stone  that 
she  had  placed  by  the  entrance.  Returning,  she  looked 
about  for  her  door,  but  not  finding  it,  apparently  mistrusted 
the  honesty  of  a  neighbor,  which  had  just  descended, 
leaving  her  own  door  temptingly  near.  She  purloined 
this  pebble  and  was  making  off  with  it,  when  the  rightful 
42 


AMMOPHILA   AND    HER    CATERPILLARS 

owner  appeared  and  gave  chase,  compelling  her  to  relin- 
quish it. 

The  things  that  struck  us  as  most  remarkable  were  the 
unerring  judgment  in  the  selection  of  a  pebble  of  precisely 
the  right  size  to  fit  the  entrance,  and  the  use  of  the  small 
pebble  in  smoothing  down  and  packing  the  soil  over  the 
opening,  together  with  the  instinct  that  taught  them  to 
remove  every  evidence  that  the  earth  had  been  dis- 
turbed. 

Since  the  Ammophiles  of  our  species  make  their  nests 
first  and  then  do  their  hunting  it  follows  that  they  must 
sometimes  carry  their  prey  for  a  considerable  distance. 
The  most  ambitious  attempt  of  this  kind  that  we  ever 
witnessed  was  made  by  gracilis. 

The  wasp  was  first  seen  carrying  a  large  green  cater- 
pillar, which  projected  at  both  ends  beyond  her  own 
body,  across  the  potato  field  at  the  lower  end  of  the  gar- 
den. We  could  not  tell  how  far  she  had  already  brought 
it,  but  judging  by  the  direction  from  which  she  was 
coming,  and  by  the  fact  that  we  had  never  seen  that 
species  of  caterpillar  in  the  garden,  she  had  probably 
come  through  the  fence  from  the  woods  beyond.  She 
moved  along  briskly  over  the  remaining  part  of  the 
potato  field,  and  then  through  an  adjoining  bean  patch 
into  the  corn  field.  This  had  been  a  place  of  much  anx- 
iety to  us  earlier  in  the  summer ;  but  now  the  corn  had 
43 


WASPS,    SOCIAL   AND    SOLITARY 

been  stacked  and  we  could  follow  her  without  difficulty. 
So  far  she  had  been  going  due  south ;  but  now  she  made 
a  turn  and  plunged  into  the  long,  tangled  grass  which 
grew  around  and  among  some  large,  overgrown  rasp- 
berry bushes.  To  keep  track  of  her  here  seemed  a  hope- 
less task,  but  we  resolved  to  do  our  best,  and  followed 
anxiously  after.  The  wasp  worked  her  way  along  about 
two  inches  above  the  ground  and  very  much  below  the 
top  of  the  grass,  clinging  to  the  blades  with  her  feet  and 
making  surprisingly  good  progress.  When  half  way 
through  the  raspberry  bushes  she  carried  the  caterpillar 
up  on  to  a  branch,  deposited  it  there,  and  after  circling 
about  to  take  her  bearings,  flew  away,  doubtless  to  visit 
her  nest  and  to  make  sure  that  she  was  going  in  the  right 
direction. 

We,  ourselves,  were  very  glad  of  the  chance  to  rest  our 
tired  eyes  and  nerves  from  the  strain  of  following  her. 
The  journey,  so  far,  had  occupied  nearly  an  hour,  at 
almost  every  instant  of  which  it  had  been  exceedingly 
difficult  to  keep  her  in  view.  But  for  our  united  efforts 
we  should  certainly  have  failed. 

While  standing  guard  over  the  caterpillar  we  noticed 
that  it  moved  its  head  from  side  to  side,  showing  that  the 
first  segment  could  not  have  been  severely  stung,  as  is 
usually  the  case  in  the  work  of  urnaria. 
44 


AMMO  PHIL  A   AND   HER    CATERPILLARS 

In  five  minutes  the  wasp  returned,  and,  with  the  air  of 
feeling  that  everything  was  right,  picked  up  her  burden 
and  carried  it  laboriously  through  the  remaining  bushes 
and  then  through  the  grassy  space  that  edged  the  garden, 
as  far  as  the  rail  fence  which  separated  this  part  of  the 
grounds  from  the  woods.  Without  a  pause  she  climbed 
on  to  this  fence  to  the  height  of  the  second  rail,  passed 
through,  and  flew  down  on  the  further  side.  Here  she 
paused  a  moment,  perhaps  to  take  breath,  and  we 
looked  at  each  other  in  some  dismay.  Whither  was  she 
leading  us  ?  We  had  now  been  following  her  for  over  an 
hour,  and  she  looked  equal  to  as  much  again  as  she 
started  off  once  more,  rapidly  this  time,  for  the  grass  was 
short  here  and  the  traveling  was  easy.  Soon,  however^  it 
became  evident  that  things  were  going  wrong,  although 
we  could  not  determine  what  was  the  matter.  The  cater- 
pillar was  laid  down  while  the  wasp  absented  herself  for 
six  minutes.  She  returned  and  carried  it  for  fifteen  min- 
utes, and  then  left  it  for  half  an  hour.  Once  more  she 
came  back,  and  carried  it  for  ten  minutes,  and  then  she 
flew  away.  It  was  now  four  o'clock,  and  we  had  been 
following  her  since  two.  We  watched  over  the  caterpillar 
for  an  hour  longer,  but  saw  no  more  of  the  wasp. 

Did  she  become  discouraged  at  the  magnitude  of  her 
task?  It  would  have  been  a  thousand  times  easier  for 
45 


WASPS,    SOCIAL   AND    SOLITARY 

her  to  have  dug  her  nest  close  by  the  place  of  capture, 
but  perhaps  she  had  one  larva  already  stored  with  her 
egg  upon  it.  The  caterpillar  was  carried  two  hundred 
and  sixty-one  feet  while  we  watched  her,  with  an  un- 
known distance  at  each  end  to  complete  the  line  between 
the  place  of  capture  and  the  nest.  She  could  scarcely 
have  lost  her  way,  since  at  every  return  she  proceeded  on 
her  journey  in  one  general  direction  without  any  hesita- 
tion. It  seems  probable  then  that  she  had  hunted  too 
far  afield,  and  did  not  realize,  when  she  started  with  her 
booty,  what  an  undertaking  it  would  be  to  carry  it  to  the 
nest.  We  once  saw  A.  vulgaris  have  a  similar  experience. 
She  was  running  along  with  a  small  green  caterpillar, 
but  became  discouraged  either  at  the  difficulty  of  finding 
her  nest,  or  at  the  distance  she  had  to  cover.  She  would 
carry  the  caterpillar  a  little  way,  drop  it,  circle  about 
a  while,  and  then  pick  it  up  again  ;  but  finally  she  gave 
up  the  whole  undertaking  and  flew  away. 

The  affairs  of  Ammophila  must  frequently  go  wrong, 
since  in  still  another  of  our  few  examples  we  saw  much 
trouble  and  labor  wasted.  The  wasp,  in  this  case  an 
urnaria,  captured  her  caterpillar  successfully  and  pro- 
ceeded to  carry  it  off.  She  was  far  from  being  in  a  hurry, 
going  along  for  a  foot  or  so,  and  then  making  a  long 
pause,  during  which  she  would  lay  it  down  and  either 
46 


AMMOPHILA   AND    HER   CATERPILLARS 

circle  above  it,  perhaps  to  take  bearings,  or  spend  the 
time  in  cleaning  herself  off,  stroking  and  smoothing 
every  part  of  her  body  with  the  utmost  care  and  deliber- 
ation. Her  stops  were  so  frequent  and  so  lengthy  that 
nearly  an  hour  was  occupied  in  going  about  twenty-five 
feet.  When,  at  last,  the  nest  was  reached,  the  plug  was 
removed  from  the  entrance  and  the  caterpillar  dragged 
in,  but  almost  immediately  the  wasp  came  out  back- 
wards with  the  point  of  an  egg  projecting  from  the  ex- 
tremity of  her  abdomen.  She  ran  around  and  around  the 
nest  in  a  distracted  way  four  or  five  times  and  then  went 
back,  dragged  the  caterpillar  out,  and  carried  it  away. 
The  egg  came  out  further  and  further,  and  finally 
dropped  on  the  ground  and  was  lost.  The  wasp,  carry- 
ing the  caterpillar,  led  us  a  long  dance,  in  a  great  semi- 
circle over  the  field,  coming  back  to  the  nest  at  last. 
Instead  of  going  in,  however,  she  was  about  to  start  off 
on  another  tour  when  we  took  her  prey  from  her  and 
placed  it  in  the  nest.  The  wasp  remained  in  the  neigh- 
borhood for  over  an  hour,  but  finally  disappeared.  The 
nest  was  not  closed,  and  when  we  dug  it  up  on  the  fol- 
lowing day  it  contained  only  the  caterpillar  that  we  had 
put  in. 

We  could  usually  enter  into  the  feelings  of  the  Ammo- 
philes  and  understand  the  meaning  of  their  actions ;  but 
47 


WASPS,   SOCIAL   AND    SOLITARY 

we  were  puzzled  once,  when  we  saw  an  urnaria  that  had 
stored  her  second  caterpillar  and  closed  her  nest  perma- 
nently, spend  the  rest  of  her  morning  in  hunting.  Why 
in  hunting  ?  She  had  not  dug  a  nest,  she  could  not  lay 
another  egg  at  once,  she  did  not  want  a  caterpillar,  for 
when  we  offered  her  one  she  stung  it  and  then  left  it  lying 
on  the  ground.  The  sun  was  bright,  the  sorrel-blossoms 
invited  her.  Surely  it  would  have  been  the  part  of  a  ra- 
tional wasp  to  have  passed  the  rest  of  the  day  in  feasting 
and  fun. 

We  have  said  that  urnaria  stores  two  caterpillars,  but 
this  rule  is  not  without  its  exception.  It  was  on  the  last 
day  of  the  summer  that  on  a  visit  to  our  dear  and  fruit- 
ful potato  field,  we  came  upon  a  wasp  of  almost  double 
the  ordinary  size,  that  made,  when  flying,  a  loud  hum 
that  at  once  attracted  attention.  She  was  just  complet- 
ing and  closing  her  nest,  and  we  determined  to  watch 
and  see  what  kind  of  a  victim  she  would  bring  in,  as 
it  seemed  improbable  that  this  great  creature  would 
content  herself  with  the  ordinary  fare  of  the  species. 
The  opening  to  the  nest  measured  half  an  inch  in  dia- 
meter. 

It  was  eleven  o'clock  when  she  flew  away.  At  half  past 
twelve  she  reappeared,  coming  from  the  direction  of  the 
woods,  opened  her  nest,  and  took  out  a  few  more  pellets. 
48 


AMMOPHILA   AND    HER    CATERPILLARS 

Then  she  flew  to  a  bush  which  grew  against  the  fence, 
three  feet  away,  and  following  her  quickly  we  saw  an 
immense  green  caterpillar  placed  high  up  on  a  branch. 
It  must  have  taken  both  strength  and  perseverance  to 
lift  this  heavy  weight  so  far  from  the  ground.  She  seized 
it  at  once  and  carried  it  down,  not  flying,  as  these  wasps 
sometimes  do  when  they  are  descending  with  a  burden, 
and  then  dragged  it  into  her  nest,  where  it  fitted  rather 
tightly.  This  nest  was  so  shallow  and  so  obliquely  di- 
rected that  the  caterpillar  was  plainly  visible  after  it  had 
been  taken  in. 

After  she  had  laid  her  egg  she  crawled  out,  getting 
past  the  caterpillar  with  some  difficulty,  and  closed  the 
nest.  There  was  certainly  no  room  for  any  further  store 
of  provisions,  and  from  the  size  of  the  caterpillar  we 
judged  that  it  would  furnish  sufficient  nourishment  even 
for  the  offspring  of  this  wasp.  We  were,  therefore,  not 
surprised,  upon  opening  the  nest  two  days  later,  to  find 
that  nothing  more  had  been  brought.  We  have  said  that 
the  wasp  larvae  spend  from  six  days  to  two  weeks  in  eat- 
ing. To  be  more  exact,  all  that  we  watched,  with  the 
exception  of  the  one  which  developed  from  the  egg  of 
this  big  creature,  ate  from  six  to  eight  days  and  then 
spun  their  cocoons ;  but  this  one  seemed  determined  to 
reach  the  size  of  its  mother,  and  ate  continuously  for 
49 


WASPS,    SOCIAL   AND    SOLITARY 

fourteen  days.  Of  course  long  before  this  time  had  ex- 
pired the  remnant  of  the  caterpillar  had  become  a  dry, 
dark- colored  mass  which  looked  little  likely  to  tempt  the 
appetite,  but  the  great  larva  ate  away  with  unabated 
relish,  gradually  acquiring  the  color  and  almost  the 
thickness  of  the  caterpillar  it  had  destroyed. 

Ammophila  polita,  which  we  have  never  seen  in  the 
country,  is  very  common  in  the  sandy  fields  to  the  south 
of  Milwaukee.  On  the  tenth  of  September,  in  bright 
clear  weather,  we  found  half  a  dozen  individuals  work- 
ing within  a  few  rods  of  each  other,  their  method  being 
similar  to  that  of  A.  yarrowii,  described  by  Dr.  Willis- 
ton,  and  having  an  especial  interest,  as  it  shows  a  transi- 
tion stage  between  the  wasps  that  provide  the  store  of 
food  all  at  once  and  those  that  feed  their  young  all 
through  the  larval  period.  Urnaria  rarely  flies  with  her 
prey ;  but  this  wasp,  although  her  caterpillars,  are  not 
very  much  smaller,  and  she  herself  is  no  larger,  carries 
her  booty  lightly  on  the  wing,  alighting  only  occasion- 
ally to  run  a  few  steps.  She  has  to  do  more  work  than 
urnaria,  taking  five  or  six  caterpillars  instead  of  two, 
and  this  method  of  progression  has  the  advantage  of 
rapidity. 

The  first  wasp  that  we  saw  was  just  alighting  with  a 
medium- sized  green  caterpillar  near  a  partly  closed 
50 


AMMOPHILA   AND    HER    CATERPILLARS 

nest.  When  disturbed  she  flew  away,  but  soon  returned, 
dropped  her  prey  half  an  inch  from  the  nest,  proceeded 
to  clear  the  opening,  ran  inside  to  see  that  all  was  right, 
and  then  backed  in  with  the  caterpillar.  Emerging  after 
a  few  minutes,  she  placed  a  small  pebble  in  the  doorway, 
which  was  thus  partly  closed,  and  flew  away.  She 
brought  three  more  caterpillars  at  intervals  of  thirty 
minutes,  and  then,  after  wedging  a  pebble  into  the  neck 
of  the  opening,  she  began  to  fill  it  in  solidly,  scratching 
in  dirt  and  packing  in  lumps  of  earth  which  were  brought 
in  her  mandibles.  We  did  not  allow  her  to  complete 
this  operation,  as  it  would  have  made  excavation  more 
difficult,  but  caught  her  and  dug  out  the  nest.  The 
tunnel  ran  down  obliquely  for  five  inches,  being  two 
inches  below  the  surface  at  the  pocket.  In  it  we  found 
a  wasp  larva,  which  was  at  least  three  days  old,  and 
four  caterpillars.  There  were  no  signs  of  the  banquet- 
ing which  must  have  already  taken  place.  We  carried 
this  larva  home  with  us,  and  it  ate  the  caterpillars  up 
clean,  finishing  with  a  fifth  which  we  supplied  from 
another  nest,  and  going  into  its  cocoon  on  September 
sixteenth.  The  caterpillars  all  wriggled  about  on  the 
slightest  stimulation,  and  remained  in  this  lively  state 
until  they  were  eaten.  They  belonged  to  four  different 
species. 


WASPS,    SOCIAL   AND    SOLITARY 

In  a  second  nest  to  which  food  was  being  carried,  we 
found  four  caterpillars  and  a  larva  about  three  days 
old,  all  the  conditions  being  like  those  in  the  other  ex- 
ample. Evidently  the  larva  had  been  fed  from  day  to 
day,  since  four  or  five  days  must  have  elapsed  since  the 
making  of  the  nest. 

Westwood  states  that  Ammophila,  when  she  has  cap- 
tured her  prey,  walks  backward,  dragging  it  after  her;1 
but  in  all  the  cases  that  came  under  our  notice  she  went 
forward,  the  caterpillar  being  grasped  near  the  anterior 
end,  in  her  mandibles,  and  either  lifted  above  the  ground 
or  allowed  to  drag  a  little  if  long  and  heavy.  It  is  usually 
held  venter  up,  but  in  one  case,  in  which  the  wasp, 
while  carrying  it  to  her  nest,  frequently  laid  it  down 
and  picked  it  up  again,  it  was  held  with  the  venter  down 
or  up  indifferently. 

The  all-important  lesson  that  Fabre  draws  from  his 
study  of  the  Ammophiles  is  that  they  are  inspired  by 
automatically  perfect  instincts,  which  can  never  have 
varied  to  any  appreciable  extent  from  the  beginning  of 
time.  He  argues  that  deviation  from  the  regular  rule 
would  mean  extinction.  For  example,  if  the  wasp  should 
sting  ever  so  little  to  one  side  of  the  median  line  the 
prey  would  be  imperfectly  paralyzed  and  the  egg  would 

1  Introduction  to  Modern  Classification  of  Insects,  ii,  189. 
52 


AMMOPHILA  AND  HER  CATERPILLARS 

consequently  be  destroyed;  or  a  sting  in  the  wrong 
place  might  cause  the  death  of  the  caterpillar  and  thus 
the  death  of  the  wasp  larva,  which,  he  thinks,  can  be 
nourished  only  by  perfectly  fresh  food. 

The  conclusions  that  we  draw  from  the  study  of  this 
genus  differ  from  these  in  the  most  striking  manner. 
The  one  preeminent,  unmistakable,  and  ever  present 
fact  is  variability.  Variability  in  every  particular,  —  in 
the  shape  of  the  nest  and  the  manner  of  digging  it,  in 
the  condition  of  the  nest  (whether  closed  or  open)  when 
left  temporarily,  in  the  method  of  stinging  the  prey,  in 
the  degree  of  malaxation,  in  the  manner  of  carrying  the 
victim,  in  the  way  of  closing  the  nest,  and  last,  and 
most  important  of  all,  in  the  condition  produced  in  the 
victims  of  the  stinging,  some  of  them  dying  and  becom- 
ing "veritable  cadavers,"  to  use  an  expressive  term  of 
Fabre's,  long  before  the  larva  is  ready  to  begin  on  them, 
while  others  live  long  past  the  time  at  which  they  would 
have  been  attacked  and  destroyed  if  we  had  not  inter- 
fered with  the  natural  course  of  events.  And  all  this 
variability  we  get  from  a  study  of  nine  wasps  and  fifteen 
caterpillars ! 

In  his  chapter  on  "Methode  des  Ammophiles"  Fabre 
says  that  each  species  has  its  own  tactics,  allowing  no 
novitiate.  "Not  one  could  have  left  descendants  if  it 
53 


WASPS,    SOCIAL    AND    SOLITARY 

were  not  the  handy  workman  of  to-day.  Any  little  slip  is 
impracticable  when  the  future  of  the  race  depends  upon 
it."  And  yet  we  find  that  the  prey  may  be  stung  so 
slightly  that  it  can  rear  and  wriggle  violently  or  so  se- 
verely that  it  dies  almost  at  once,  and  in  neither  case  is 
a  break  made  in  the  generations  of  the  Ammophiles, 
since  in  the  former  the  egg  or  larva  is  so  firmly  fastened 
as  to  keep  its  hold,  while  in  the  latter  the  dead  and  de- 
composing caterpillar  is  eaten  without  dissatisfaction  or 
injury. 

Nor  do  we,  in  gathering  evidence  for  the  evolution  of 
the  instincts  of  these  wasps,  need  to  rely  entirely  upon 
our  own  observations.  Fabre  himself  gives  many  facts 
which  point  in  the  same  direction,  but  he  draws  a  line 
between  those  actions  which  are  the  result  of  mechanical 
and  unvarying  instinct  and  those  which  come  within  the 
sphere  of  reason,  and  in  relation  to  which  the  insect  must 
consider,  compare,  and  judge.  Yet  this  line,  even  in  the 
light  of  his  own  work,  is  so  extremely  variable,  needing 
readjustment  with  every  new  species  and  often  among 
the  individuals  of  the  same  species,  that  it  loses  for  others 
the  meaning  which  it  has  for  its  author.  He  himself 
speaks  of  certain  individuals  of  the  genus  Sphex  which 
refuse  to  be  duped  when  he  withdraws  their  prey  to  a 
distance,  These,  he  says,  are  the  elite,  the  strong- 
54 


AMMOPHILA  AND   HER   CATERPILLARS 

headed  ones,  which  are  able  to  recognize  the  malice  of 
the  action  and  govern  themselves  accordingly,  but  these 
revolutionists,  apt  at  progress,  he  goes  on  to  say,  are  few 
in  numbers.  The  others,  the  conservators  of  old  usages 
and  customs,  are  the  majority,  the  crowd.  Yes,  but  is  it 
not  always  the  strong-minded  few  that  direct  the  destiny 
of  a  race  ? 


Chapter  III 

THE    GREAT   GOLDEN    DIGGER 

THIS  wasp  (Sphex  ichneumonea  Linn.)  is  one  of 
our  most  beautiful  species,  its  great  size  and  its 
brilliant  color,  as  it  flies  among  the  flowers,  serving  to 
make  it  well  known  to  all  observers  of  nature.  During 
the  later  part  of  July,  all  through  August,  and  even  in  the 
early  days  of  September  it  is  commonly  found  at  work 
making  or  storing  its  burrow.  It  is  rare  in  our  garden, 
however,  and  we  thought  ourselves  fortunate  in  being 
able  to  keep  track  of  one  individual  from  the  making  to 
the  closing  of  the  nest.  Although  large  and  powerful  it 
is  gracefully  formed.  In  color  it  is  brown,  varied  with 
bright  yellow. 

On  the  morning  of  the  third  of  August,  at  a  little  after 
ten  o'clock,  we  saw  one  of  these  hunters  start  to  dig  a 
nest  on  the  side  of  a  stony  hill.  After  making  some  pro- 
gress in  the  work  she  flew  off  and  selected  a  second  place, 
where  she  dug  so  persistently  that  we  felt  confident  that 
this  was  to  be  her  final  resting-place ;  but  when  the  hole 
56 


THE    GREAT    GOLDEN    DIGGER 

was  two  and  one  half  inches  deep,  it  too  was  deserted. 
Again  our  wasp  chose  a  spot  and  began  to  burrow.  She 
worked  very  rapidly,  and  at  twenty  minutes  before  twelve 
the  hole  was  three  inches  deep.  At  high  noon  she  flew 
away,  and  was  gone  forty  minutes.  The  day  was  exces- 
sively hot,  about  98°  Fahr.,  and  we  ourselves  were  only 
deterred  from  taking  a  noonday  rest  by  our  fixed  deter- 
mination not  to  leave  the  place  until  we  had  seen  all  that 
there  was  to  be  seen  in  the  manoeuvres  of  ichneumonea. 
On  returning  she  appeared  very  much  excited,  fairly 
quivering  with  vitality  as  she  resumed  her  work.  She 
came  up  backward,  carrying  the  earth  with  her  mouth 
and  anterior  legs,  and  went  back  from  the  opening  some 
little  distance,  when  it  was  dropped,  and  she  at  once 
went  in  again.  While  in  the  burrow  we  could  hear  her 
humming,  just  as  the  Pelopaei  do  when,  head  downward 
in  the  wet  mud,  they  gather  their  loads  for  nest-building. 
In  five  or  six  trips  a  little  mass  of  earth  would  accumu- 
late, and  then  she  would  lie  quite  flat  on  the  heap  and 
kick  the  particles  away  in  all  directions.  As  the  work 
progressed  the  earth  was  carried  further  and  further 
away  before  it  was  placed  on  the  ground,  and  as  she 
backed  in  different  directions  the  material  brought  out 
was  well  spread  about  from  the  down-hill  side  of  the 
nest.  Sometimes  she  would  spend  several  moments  in 
57 


WASPS,    SOCIAL    AND    SOLITARY 

smoothing  the  debris  all  around,  so  that  the  opening 
presented  much  the  appearance  of  an  immense  ant-hill, 
only  the  particles  were  much  larger.  During  the  first 
hour  that  we  watched  her  she  frequently  turned  directly 
toward  us,  and,  sometimes  remaining  on  the  ground  and 
sometimes  rising  on  her  wings  to  a  level  with  our  faces, 
appeared  to  be  eyeing  us  intently  for  four  or  five  seconds. 
Her  attitude  was  comical,  and  she  seemed  to  be  saying, 
"Well,  what  are  you  hanging  around  here  for?" 

As  the  afternoon  wore  on  she  worked  more  calmly 
and  her  fidgety  and  excited  manner  disappeared,  the 
excavation  progressing  steadily  until  half-past  three. 
At  that  time  she  came  out  and  walked  slowly  about  in 
front  of  her  nest  and  all  around  it.  Then  she  rose  and 
circled  just  above  it,  gradually  widening  her  flight,  now 
going  further  afield  and  now  flying  in  and  out  among 
the  plants  and  bushes  in  the  immediate  vicinity.  The 
detailed  survey  of  every  little  object  near  her  nest  was 
remarkable  ;  and  not  until  her  tour  of  observation  had 
carried  her  five  times  entirely  around  the  spot  did  she 
appear  satisfied  and  fly  away.  All  her  actions  showed 
that  she  was  studying  the  locality  and  getting  her  bear- 
ings before  taking  her  departure.  A  fact  that  impressed 
us  very  much  was  that  with  the  two  nests  that  she  had 
begun  and  then  deserted  she  had  taken  no  such  precau- 
58 


THE    GREAT    GOLDEN    DIGGER 

tion,  but  simply  came  up  and  flew  off.  Had  she  made 
up  her  mind,  if  we  may  be  allowed  to  use  the  term,  that 
the  localities  were  in  some  way  unsuitable  and  that 
hence  she  had  no  occasion  to  return  to  them  ?  Had  she 


THOROUGH    LOCALITY   STUDY   BY   SPHEX 

decided,  in  the  last  instance,  that  she  would  return  and 
so  must  get  her  bearings?  We  wondered  how  far  the 
different  acts  were  instinctive,  or  were,  as  Huber  has  it, 
an  evidence  of  a  "little  dose  of  judgment."  Bates,  in 
speaking  of  Monedula  signata,  says  that  he  often  no- 
ticed it  taking  a  few  turns  about  the  locality  of  its  nest, 
and  that  he  was  convinced  that  it  was  doing  so  for  the 
purpose  of  getting  its  bearings.  Belt,  having  described 
59 


WASPS,    SOCIAL    AND    SOLITARY 

how  he  fed  a  specimen  of  Polistes  carnifex  with  a  cater- 
pillar, which  the  wasp  cut  into  two  parts,  goes  on  to  say: 
"Being  at  the  time  amidst  a  thick  mass  of  fine-leaved 
climbing  plant,  it  proceeded,  before  flying  away,  to  take 
note  of  the  place  where  it  was  leaving  the  other  half.  To 
do  this,  it  hovered  in  front  of  it  for  a  few  seconds,  then 
took  small  circles  in  front  of  it,  then  larger  ones  around 
the  whole  plant.  I  thought  it  had  gone,  but  it  returned 
again,  and  had  another  look  at  the  opening  in  the  dense 
foliage  down  which  the  other  half  of  the  caterpillar  lay." 1 
He  then  remarks  that  when  the  wasp  came  back  for  the 
remaining  half  it  flew  straight  to  its  nest  without  taking 
any  further  note  of  the  locality.  Both  of  these  writers 
believe  that  many  of  the  actions  of  insects  that  are 
ascribed  to  instinct  are  really  evidence  of  the  possession 
of  a  certain  amount  of  intelligence. 

To  return  to  our  Sphex.  When  she  flew  away  we  nat- 
urally supposed  that  she  had  gone  in  search  of  her  prey, 
and  we  were  on  the  qui  vive  to  observe  every  step  in  her 
actions  when  she  came  home.  Alas!  when  she  came  back 
half  an  hour  later,  she  was  empty-handed.  She  dug  for 
four  minutes,  then  flew  off  and  was  gone  two  minutes, 
then  returned  and  worked  for  thirty-five  minutes.  An- 
other two  minutes'  excursion,  and  then  she  settled  down 

1  Naturalist  in  Nicaragua,  p.  1 36. 
60 


THE    GREAT    GOLDEN    DIGGER 

to  work  in  good  earnest  and  brought  up  load  after  load 
of  earth  until  the  shadows  grew  long.  We  noticed  that 
on  these  later  trips  she  flew  directly  away,  depending 
upon  her  first  careful  study  of  the  surroundings  to  find 
her  way  back.  At  fifteen  minutes  after  five  the  patient 
worker  came  to  the  surface,  and  made  a  second  study, 


HASTY    LOCALITY   STUDY   BY   SPHEX 


this  time  not  so  detailed,  of  the  environment.  She  flew 
this  way  and  that,  in  and  out  among  the  plants,  high  and 
low,  far  and  near,  and  at  last,  satisfied,  rose  in  circles, 
higher  and  higher,  and  disappeared  from  view.  We 
waited  for  her  return  with  all  the  patience  at  our  com- 
61 


WASPS,    SOCIAL    AND    SOLITARY 

mand,  from  fifteen  minutes  after  five  until  fifteen  min- 
utes before  seven.  We  felt  sure  that  when  she  came 
back  she  would  bring  her  victim  with  her,  and  when  we 
saw  her  approaching  we  threw  ourselves  prone  on  the 
ground,  eagerly  expecting  to  see  the  end  of  the  drama ; 
but  her  search  had  been  unsuccessful,  —  she  carried 
nothing.  In  the  realms  of  wasp-life,  disappointments 
are  not  uncommon,  and  this  tune  she  had  us  to  share 
her  chagrin,  for  we  felt  as  tired  and  discouraged  as  she 
perhaps  did  herself.  When  we  saw  her  entering  without 
any  provision  for  her  future  offspring,  we  were  at  a,  loss 
what  to  do  next ;  and  it  may  be  that  this  state  of  mind 
was  shared  by  her  also,  for  she  at  once  began  to  fill  in  the 
entrance  to  her  nest.  We  now  thought  it  time  to  act, 
and  decided  to  capture  her,  to  keep  her  over  night  in 
one  of  our  wasp-cages,  and  to  try  to  induce  her  to  re- 
turn to  her  duty  on  the  following  day.  We  therefore 
secured  her  in  a  large  bottle,  carried  her  to  the  cottage, 
and  having  made  every  possible  arrangement  for  her 
comfort,  left  her  for  the  night. 

On  the  next  morning,  at  half  after  eight  o'clock,  we 
took  Lady  Sphex  down  to  her  home,  and  placed  the 
mouth  of  the  bottle  so  that  when  she  came  out  she  had 
to  enter  the  nest.  This  she  did,  remaining  below,  how- 
ever, only  a  moment.  When  she  came  up  to  the  surface 
62 


SPHEX    DRAGGING    GRASSHOPPER    TO    HER    NEST 


THE    GREAT    GOLDEN    DIGGER 

she  stood  still  and  looked  about  for  a  few  seconds,  and 
then  flew  away.  It  surprised  us  that  having  been  ab- 
sent from  the  place  for  so  many  hours,  she  made  no 
study  of  the  locality  as  she  had  done  before.  We  thought 
it  a  very  unpromising  sign,  and  had  great  fears  that  she 
was  deserting  the  place  and  that  we  should  see  her  no 
more.  One  would  need  to  watch  a  wasp  through  the 
long  hours  of  a  broiling  hot  day  to  appreciate  the  joy 
that  we  felt  when  at  nine  o'clock  we  saw  her  coming 
back.  She  had  no  difficulty  in  finding  her  nest,  nor  did 
she  feel  any  hesitation  as  to  what  ought  to  be  done  next, 
but  fell  to  work  at  once  at  carrying  out  more  dirt.  The 
weather,  although  still  hot,  had  become  cloudy  and  so 
threatening  that  we  expected  a  down- pour  of  rain  every 
moment,  but  this  seemed  to  make  no  difference  to  her. 
Load  after  load  was  brought  up,  until,  at  the  end  of  an 
hour,  everything  seemed  completed  to  her  satisfaction. 
She  came  to  the  entrance  and  flew  about,  now  this  way, 
and  now  that,  repeating  the  locality  study  in  the  most 
thorough  manner,  and  then  went  away.  At  the  expira- 
tion of  an  hour  we  saw  her  approaching  with  a  large 
light  green  meadow-grasshopper,  which  was  held  in  the 
mouth  and  supported  by  the  fore  legs,  which  were  folded 
under.  On  arriving,  the  prey  was  placed,  head  first,  near 
the  entrance,  while  the  wasp  went  in,  probably  to  reas- 
65 


WASPS,    SOCIAL    AND    SOLITARY 

sure  herself  that  all  was  right.  Soon  she  appeared  at  the 
door  of  the  nest  and  remained  motionless  for  some  mo- 
ments, gazing  intently  at  her  treasure.  Then  seizing  it 
(we  thought  by  an  antenna)  she  dragged  it  head  first 
into  the  tunnel. 

The  laying  of  the  egg  did  not  detain  her  long.  She 
was  up  in  a  moment  and  began  at  once  to  throw  earth 
into  the  nest.  After  a  little  she  went  in  herself,  and  we 
could  plainly  hear  her  humming  as  she  pushed  the  loose 
material  down  with  her  head.  When  she  resumed  the 
work  outside  we  interrupted  her  to  catch  a  little  fly  that 
we  had  already  driven  off  several  times  just  as  it  was 
about  to  enter  the  nest.  The  Sphex  was  disturbed  and 
flew  away,  and  this  gave  us  an  opportunity  to  open  the 
burrow.  The  grasshopper  was  placed  on  its  back,  with 
its  head  next  to  the  blind  end  of  the  pocket  and  the  legs 
protruding  up  into  the  tunnel. 

We  found  that  the  egg  of  the  wasp,  which  was  seven 
millimeters  long,  and  rather  slender,  was  placed  on  the 
under  face  of  the  thorax  at  a  right  angle  to  its  length, 
and  parallel  with  the  femur  of  the  second  leg.  This  leg 
had  apparently  been  stung  so  that  it  had  swollen  and 
folded  over  the  free  end  of  the  egg,  which  was  thus  firmly 
held  in  place  at  both  extremities.  *  Upon  examination 

1  Fabre  says  that  all  of  the  three  species  of  Sphex  that  he  has 
66 


THE    GREAT    GOLDEN    DIGGER 

we  found  that  the  abdomen  of  the  grasshopper  was  beat- 
ing regularly  and  automatically,  but  the  closest  obser- 
vation failed  to  discover  any  other  movements,  nor 
would  any  part  respond  when  stimulated.  At  three 
o'clock  in  the  afternoon  we  found  the  abdomen  still 
pulsating,  and,  in  addition,  that  both  antennae  moved 
several  times  when  we  lifted  off  the  cover  of  the  jar  that 
contained  the  insect.  On  the  next  morning  the  grass- 
hopper was  very  lively,  the  antennae  and  labial  palpi 
moving  without  stimulation.  It  had  passed  faeces,  and 
was  able  to  lift  its  abdomen,  which  was  curved  over  to- 
ward the  head,  as  it  lay  on  its  back,  frequently  and  with 
considerable  violence.  On  the  next  afternoon  there  was 
no  change  in  the  movements,  but  the  egg  was  dead.  On 
the  seventh  the  grasshopper  responded  to  stimulation 
by  a  slight  movement  of  the  palpi  and  the  end  of  the 
abdomen.  The  pulsation  of  the  abdomen  continued 
until  the  afternoon  of  the  eighth,  when  it  ceased,  no  effort 
of  ours  succeeding  in  starting  it  again.  The  movements 
of  the  antennae  and  palpi  grew  weaker  and  weaker  on 
the  ninth,  and  on  the  morning  of  the  tenth  the  insect 

studied  lay  the  egg  on  this  identical  place.  He  places  immense  impor- 
tance on  this  point,  which  seems  to  us  rather  fanciful.  He  also  no- 
ticed the  pulsation  of  the  abdomen  and  the  movements  of  the  other 
parts. 

67 


WASPS,    SOCIAL   AND   SOLITARY 

was  dead,  a  period  of  five  and  a  half  days  having  elapsed 
since  it  was  brought  into  the  nest. 

We  had  not  supposed  that  the  digging  up  of  her  nest 
would  much  disturb  our  Sphex,  since  her  connection 
with  it  was  so  nearly  at  an  end  ;  but  in  this  we  were  mis- 
taken. When  we  returned  to  the  garden  about  half  an 
hour  after  we  had  done  the  deed,  we  heard  her  loud  and 
anxious  humming  from  a  distance.  She  was  searching 
far  and  near  for  her  treasure  house,  returning  every  few 
minutes  to  the  right  spot,  although  the  upturned  earth 
had  entirely  changed  its  appearance.  She  seemed  unable 
to  believe  her  eyes,  and  her  persistent  refusal  to  accept 
the  fact  that  her  nest  had  been  destroyed  was  pathetic. 
She  lingered  about  the  garden  all  through  the  day,  and 
made  so  many  visits  to  us,  getting  under  our  umbrellas 
and  thrusting  her  tremendous  personality  into  our  very 
faces,  that  we  wondered  if  she  were  trying  to  question  us 
as  to  the  whereabouts  of  her  property.  Later  we  learned 
that  we  had  wronged  her  more  deeply  than  we  knew. 
Had  we  not  interfered  she  would  have  excavated  several 
cells  to  the  side  of  the  main  tunnel,  storing  a  grasshopper 
in  each.  Who  knows  but  perhaps  our  Golden  Digger, 
standing  among  the  ruins  of  her  home,  or  peering  under 
our  umbrella,  said  to  herself:  " Men  are  poor  things: 
I  don't  know  why  the  world  thinks  so  much  of  them." 
68 


THE    GREAT    GOLDEN    DIGGER 


Dr.  Packard  describes  Sphex  ichneumonea  as  nesting 
in  gravelly  walks,  where  it  digs  to  a  depth  of  from  four 
to  six  inches,  using  its  jaws  and  fore  legs  to  do  the  ex- 
cavating. While  the  wasps  that  he  observed  completed 
the  hole  in  half  an  hour,  ours  was  actually  at  work  a  little 
over  four  hours.  Her  nest, 
as  is  shown  in  the  drawing, 
measured  seven  and  one  half 
inches  to  the  beginning  of 
the  pocket,  which  was  three 
quarters  of  an  inch  wide  by 
one  and  one  half  inches  long. 
The  yellow-winged  Sphex,  a 
native  of  France,  was  found 
by  Fabre  to  take  several 
hours  to  make  her  nest,  work- 
ing in  hard  ground  ;  while 
another  species,  also  studied 
by  this  observer,  dug  in  soft 
earth,  either  in  the  ground  or  in  the  accumulations  on 
the  roofs  of  buildings,  and  completed  her  work  in  fifteen 
minutes  at  the  most.  These  variations  in  the  habits  of 
closely  related  species  should  be  carefully  studied  in 
any  attempt  toward  an  explanation  of  their  instincts. 

Fabre' s  account  of  the  genus  Sphex,  as  it  appears  in 
69 


NEST   OF   SPHEX 


WASPS,    SOCIAL   AND    SOLITARY 

France,  is  most  interesting.  He  says  that  the  yellow- 
winged  species,  living  in  colonies,  first  digs  her  nest 
and  then  secures  her  cricket,  which  is  brought,  on  the 
wing,  to  the  neighborhood  of  the  burrow,  the  last  part 
of  the  journey  being  accomplished  on  foot.  The  cricket 
is  dragged  by  one  of  the  antennae,  and  is  not  left  until 
the  nest  is  reached.  It  is  then  placed  so  that  the  antennae 
reach  precisely  to  the  opening,  and  there  it  is  left  while 
the  wasp  descends  hurriedly  into  the  depths  of  the  bur- 
row. In  a  few  seconds  she  reappears,  showing  her  head 
outside,  seizes  the  antennae  of  the  cricket,  and  drags  it 
below.  These  manoeuvres  are  repeated  with  a  striking 
degree  of  invariability. 

The  other  Sphex  first  secures  her  prey,  which  is  too 
large  and  heavy  to  be  carried  far,  and  then  digs  her 
nest  in  the  neighborhood  of  the  capture.  This  being 
done,  she  returns  to  her  victim,  and  straddling  it  drags 
it  by  one  or  both  of  the  antennae.  Sometimes  the  whole 
journey  is  accomplished  at  once,  but  oftener  the  wasp 
suddenly  drops  her  burden  and  runs  rapidly  to  her 
nest.  Perhaps  it  seems  to  her  that  the  entrance  is 
not  large  enough  to  accommodate  a  creature  of  such 
size;  perhaps  she  imagines  some  imperfections  of  detail 
which  would  impede  the  process  of  storing  it  up.  The 
work  is  retouched,  the  doorway  enlarged,  the  threshold 
70 


THE    GREAT    GOLDEN    DIGGER 

smoothed.  Then  she  returns  to  her  booty  and  again 
starts  with  it.  After  a  few  steps  the  Sphex  seems  to  be 
seized  with  another  idea.  She  has  visited  the  doorway, 
but  has  not  seen  the  interior.  Who  knows  whether  all 
is  well  within?  She  drops  her  prey  and  again  runs  off. 
The  visit  to  the  interior  is  made,  more  touches  are  given, 
and  once  more  she  returns.  Will  the  journey  be  accom- 
plished this  time?  Impossible  to  say.  Some  wasps, 
more  given  to  worry  than  others  or  more  forgetful  of 
the  small  details  of  architecture,  to  repair  their  neglect 
or  to  clear  up  their  suspicions,  abandon  their  booty  five 
or  six  times  in  succession  to  retouch  the  nest  or  simply 
to  visit  the  interior.  The  prey,  once  brought  to  the 
nest,  is  carried  in  without  the  preliminaries  that  are 
common  to  the  other  species. 


Chapter  IV 

SEVERAL    LITTLE  WASPS 

IN  a  search  for  the  nest  of  one  of  our  garden  wasps 
we  found,  in  the  woods  beyond  the  fence,  an  old, 
weather-beaten  stump  which  was  riddled  with  holes 
both  large  and  small.  The  large  ones  were  evidently 
the  passage-ways  of  ants,  and  were  in  constant  use.  The 
small  ones  seemed  to  be  uninhabited  ;  but  thinking  they 
might  contain  the  nests  we  were  in  search  of,  and  hop- 
ing that  if  we  watched  long  enough  we  might  see  our 
wasps  flitting  in  and  out,  we  settled  ourselves  close  by. 
We  were  resolved  to  stay  as  long  as  was  necessary,  and 
we  blessed  the  fate  that  made  it  our  duty  to  sit  on  the 
grass  under  the  shade  of  a  wide-spreading  oak  rather 
than  in  the  distressing  glare  and  heat  of  the  garden  ;  for 
this  was  on  the  tenth  of  July,  and  the  weather  was  what 
the  farmers  call  "seasonable." 

Twenty,  thirty,  forty  minutes  passed.  Our  eyes  ached 

with  persistent  gazing,  and  we  had  nearly  made  up  our 

minds  that  the  likely-looking  little  holes  were  unten- 

anted,  when  lo !  a  tiny  wasp,  carrying  something  which 

72 


SEVERAL  LITTLE    WASPS 

we  could  not  see  distinctly,  darted  into  one  of  them.  It 
was  gone  so  quickly  that  we  could  not  be  sure  that  it 
was  the  species  we  were  looking  for,  and  when  it  re- 
appeared, after  two  or  three  minutes,  we  saw  that  it  was 
not.  This  point  being  determined,  we  watched  the  hole 
with  redoubled  interest. 

It  was  wearisome  work,  for  the  wasp  stayed  away  a 
long  time,  and  we  dared  not  let  our  gaze  wander  lest  she 
should  slip  in  without  our  knowledge.  At  the  end  of 
thirty-five  minutes  she  returned,  but  again  we  failed 
to  see  what  she  carried.  She  flew  with  great  rapidity, 
and  we  scarcely  caught  sight  of  her  before  she  vanished 
into  her  nest.  We  could  not  but  wonder  at  the  ease  and 
certainty  with  which  she  recognized  her  own  doorway 
among  the  hundreds  of  holes  on  the  side  of  the  stump. 
This  power  of  localization,  while  it  is  one  of  the  most 
common  among  wasps,  is  surely  also  one  of  the  most 
remarkable. 

Our  little  Rhopalum  pedicellatum,  for  that  proved  to 
be  her  name,  made  six  more  journeys  within  the  next 
two  hours.  At  the  end  of  this  time  we  opened  the  tunnel, 
and,  after  a  great  deal  of  sawing  and  cutting,  succeeded 
in  finding  the  nest  five  inches  from  the  surface.  It  was 
nothing  but  a  slight  enlargement  of  the  gallery,  in  the 
soft  decaying  wood.  In  it  we  found  thirty-three  gray 
73 


WASPS,    SOLITARY   AND    SOCIAL 

gnats,  all  of  them,  except  two,  being  dead.  On  one  of 
the  dead  ones  was  the  egg,  which  had  probably  been 
laid  within  a  few  hours. 

The  egg  hatched  two  days  later,  on  July  twelfth,  but 
on  the  fifteenth  the  larva  died.  By  this  time  many  of  the 
gnats  looked  very  dry,  although  we  had  tried  to  arrange 
for  both  moisture  and  ventilation  by  packing  the  bottom 
of  the  tube  with  pith  and  covering  the  top  with  muslin. 

Further  watching  gave  us  one  more  wasp  of  this 
species,  in  the  same  stump.  This  time  the  nest  was  only 
two  inches  from  the  surface.  It  contained  four  dead 
gnats  and  two  live  ones,  but  no  egg,  showing  that  the  egg 
is  not  always  laid  on  the  first  ones  stored. 

Much  later  in  the  season,  toward  the  end  of  August, 
we  found  another  species  of  Rhopalum  which  proved  to 
be  new,  and  for  which  Mr.  Ashmead  has  proposed  the 
name  rubrocinctum,  since  it  wears  a  red  girdle  around 
the  front  end  of  the  abdomen,  being  otherwise  dressed  in 
black  like  pedicillatum.  It  makes  its  home  in  the  stalks 
of  raspberry  bushes.  We  opened  a  stem  which  contained 
thirteen  compartments,  separated  by  partitions  of  pith. 
These  were  filled  with  black,  gray,  and  green  gnats, 
which  were  packed  in  so  closely  that  they  were  doubled 
over  and  pressed  out  of  shape.  Each  cell  contained 
from  twenty-five  to  thirty  gnats.  In  some  of  them  were 
74 


SEVERAL   LITTLE  WASPS 

cocoons,  in  others  larvae,  and  in  one  was  an  egg.  The 
gnats  were  very  carefully  examined,  and  all  of  them, 
from  the  cells  that  had  been  filled  last  as  well  as  from 
those  provisioned  earlier,  were  dead. 

Other  species  of  Rhopalum  are  said  to  prey  upon 
spiders  and  aphides. 

In  studying  the  species  that  come  in  our  way  we  are 
continually  developing  distinct  likings  for  some  kinds 
above  others.  The  ap- 
pearance of  one  of 
these  favorites  is  al- 
ways hailed  with  de- 
light, and  when  the 
season's  work  is  over 
we  remember  them 
with  lively  pleasure. 

OXYBELUS   QUADRINOTATUS 

It  is  thus,  dear  little 

OxvMus,  that  we  dwell  upon  the  thought  of  you  and 
your  pretty  ways.  No  other  wasp  rose  so  early  in  the 
morning,  no  other  was  so  quick  and  tidy  about  her 
work,  so  apt  and  business-like  without  any  fuss  or 
flurry.  No  other  was  more  rapid  and  vigorous  in  pur- 
suit of  her  prey,  and  we  think  with  admiration  and 
gratitude  of  the  number  of  flies  that  you  must  have 
destroyed  in  the  course  of  the  summer. 
75 


WASPS,    SOLITARY   AND    SOCIAL 

O.  quadrinotatus  is  only  one-quarter  of  an  inch  long, 
and  is  dark  gray  with  four  whitish  spots  on  the  abdomen. 
It  was  before  nine  o'clock  in  the  morning  that,  while  out 
on  an  early  inspection  tour  in  the  garden,  we  saw  one  of 
these  wasps  descend  upon  a  sandy  spot,  and  after  a  mo- 
ment's rapid  scratching  with  her  first  legs  enter  the  hole 
that  she  had  opened.  Under  her  body  she  was  carrying  a 
fly  which  looked  like  the  common  domestic  species.  It 
was  upside  down,  its  head  being  tightly  clasped  with  the 
third  pair  of  legs,  and  all  of  its  abdomen  projected  be- 
yond the  abdomen  of  the  wasp.  Ashmead  quotes  from 
Fabre  the  remarkable  statement  that  Oxybelus  carries 
her  flies  home  impaled  on  her  sting,  an  idea  that  prob- 
ably arose  from  the  fact  that  nearly  the  whole  body  of 
the  fly  is  visible. 

Our  new-found  wasp  stayed  only  a  moment  in  her 
nest,  although,  as  we  afterward  found,  it  was  long 
enough  for  her  to  lay  her  egg  on  the  fly.  When  she  came 
out  she  quickly  smoothed  the  sand  over  the  spot  with 
her  head  and  legs  so  that  there  was  nothing  to  mark  the 
nest,  and  flew  away.  In  three  minutes  she  returned  with 
another  fly.  She  alighted  two  or  three  inches  away,  and 
scratched  for  an  instant,  but  quickly  saw  her  mistake, 
and  found  the  right  spot. 

Again  and  again  the  pretty  little  worker  went  and 
76 


SEVERAL  LITTLE  WASPS 

came,  while  we  sat  watching  close  by,  admiring  her  deft 
handiwork  in  opening  and  closing  the  nest  and  wonder- 
ing at  the  ease  with  which  she  found  it  at  each  return. 
There  was  nothing  tiresome  or  dilatory  about  this 
species,  and  within  twenty  minutes  we  had  seen  six  flies 
stored  up.  The  nest  was  closed  and  the  place  smoothed 
over  every  time  before  she  went  away,  but  when  she 
entered  she  left  the  door  open  behind  her.  We  once  tried 
to  make  her  drop  the  fly,  but  when  disturbed  she  flew  up 
and  alighted  on  a  plant  near  by,  keeping  her  hold  on 
it.  The  whole  performance  was  brisk  and  business- 
like, but  without  the  feverish  hurry  of  Ammophila  and 
Pompilus. 

After  the  sixth  fly  was  taken  in  we  were  afraid  to  let 
her  go  again,  thinking  that  the  nest  must  now  be  com- 
pletely provisioned,  and  that  she  would  not  return.  She 
was  such  a  charming  little  wasp,  scarcely  bigger  than  a 
fly  herself  and  yet  so  useful  in  her  industry,  that  we 
hated  to  disturb  her ;  but  as  we  were  obliged  to  have  her 
for  identification  we  first  caught  her,  and  then  opened 
the  nest.  It  contained  only  the  flies  that  we  had  seen 
taken  in,  the  egg  being  attached  to  the  one  lowest  down, 
on  the  left  side,  between  the  head  and  the  thorax.  It  was 
long  and  cylindrical.  The  flies  were  dead,  but  showed 
no  marks  of  violence.  We  learned  later  that  it  takes 
77 


WASPS,    SOLITARY   AND    SOCIAL 

Oxybelus  two  hours  to  make  her  nest  so  that  this  one 
must  have  been  prepared  the  day  before. 

The  egg,  which  was  laid  just  before  nine  o'clock  on  the 
morning  of  August  seventh,  hatched  at  a  little  after  nine 
on  the  morning  of  August  eighth.  The  larva  began  to 
eat  at  once,  and  devoured  all  the  inside  of  the  .thorax 
and  abdomen  of  the  fly  to  which  it  was  attached,  in  the 
first  twenty-four  hours.  On  August  twelfth  it  had 
reached  the  sixth  fly,  and  we  supplied  it  with  three  more. 
On  August  fourteenth  these  were  gone,  and  we  again 
replenished  its  larder,  this  time  with  two  flies.  The  larva 
had  partly  eaten  these  when  something  went  wrong.  Its 
appetite  failed,  and  on  August  sixteenth  it  died. 

On  further  acquaintance  this  wasp  lost  none  of  her 
charm,  —  indeed,  she  gained  in  interest  from  the  almost 
human  curiosity  that  she  showed  about  the  affairs  of 
other  people.  Where  several  were  living  close  together 
one  of  them  would  sometimes  stop  digging  her  own  nest 
to  perch  on  a  weed  and  watch  the  labor  of  another,  and 
we  once  saw  an  especially  inquisitive  character  burrow 
through  the  closed  door  and  enter  the  home  of  her  next- 
door  neighbor. 

We  find  but  meagre  notes  on  the  genus  Oxybelus. 
Ashmead  says  that  no  observations  have  been  made  on 
the  American  species,  but  that  in  Europe  they  are  found 
78 


SEVERAL   LITTLE    WASPS 

to  burrow  in  sand  and  to  provision  their  nests  with  dip- 
terous insects.  He  says  also  that  according  to  Verhoeff 
the  species  in  this  genus  do  not  paralyze  their  prey  by 
stinging,  as  they  are  unable  to  do  so  on  account  of  the 


NEST    OF   OXYBELUS 


rigidity  of  the  abdomen,  but  that  instead  they  crush  the 
thorax  with  the  mandibles  just  beneath  the  wings,  the 
centre  of  the  nervous  ganglia.  He  found  in  one  nest  a 
dozen  flies,  and  all  had  the  thorax  crushed  and  were 
dead.  In  the  case  of  our  wasp  we  do  not  know  how  the 
flies  were  killed,  but  there  was  no  crushing  of  the  tho- 
rax. The  larva  devoured,  in  all,  ten  flies.  At  the  time  of 
its  death  it  had  probably  finished  the  larval  stage  of  its 
79 


WASPS,    SOCIAL   AND    SOLITARY 

existence,  since  nine  days  had  elapsed  since  the  hatching 
of  the  egg.  It  may  be  that  this  period  just  before  pupa- 
tion is  a  critical  point  in  the  life  history  of  a  wasp,  for  we 
lost  several  of  our  nurslings  at  this  time,  and  Fabre  has 
noted  that  when,  on  account  of  the  presence  of  parasites, 
the  larva  of  Bembex  rostrata  had  lacked  something  of 
its  usual  amount  of  nourishment,  it  perished  miserably 
at  the  end  of  its  larval  stage,  not  having  strength  enough 
to  spin  its  cocoon.  No  waspling  in  our  charge  ever 
died  from  lack  of  nourishment  —  on  that  score  our 
consciences  are  clear  ;  but  it  was  difficult  to  make  their 
conditions  quite  normal,  and  for  this  reason  we  may 
have  been,  indirectly,  the  cause  of  their  death. 

The  way  in  which  our  Oxybelus  carries  its  prey  is  pe- 
culiar to  itself.  Bembex  and  Philanthus  also  hold  their 
prey  under  the  body,  but  use  the  second  pair  of  legs,  so 
that  it  does  not  project  behind  except  at  the  moment  of 
entrance  into  the  nest.  Quadrinotatus,  as  we  could  dis- 
tinctly see,  since  she  passed  close  to  us  several  times  in 
quick  succession,  clasps  the  head  of  her  victim  in  the 
third  pair  of  legs,  and  flying  thus,  with  its  whole  body 
sticking  out  behind  her,  she  certainly  presents  a  very 
remarkable  appearance. 

Aporus  fasciatus  is  a  dark  gray  species,  and  is  less  than 
half  an  inch  in  length.  We  were  working  one  hot  day  in 
80 


SEVERAL   LITTLE   WASPS 

the  melon  field,  when  we  saw  one  of  these  little  wasps 
going  backward  and  dragging  a  female  of  Msevia  vittata 
which  was  much  larger  than  she  was  herself.  She  twice 
left  it  on  the  ground  while  she  circled  about  for  a  mo- 
ment, but  soon  carried  it  up  on  to  one  of  the  large  melon 
leaves,  and  left  it  there 
while  she  made  a  long  and 
careful  study  of  the  local- 
ity, skimming  close  to  the 
ground  in  and  out  among 
the  vines;  at  length  she 
went  under  a  leaf  that  lay 
close  to  the  ground  and 
began  to  dig.  After  her 
head  was  well  down  in  the 
ground  we  broke  off  the 

...  .     ,  .  APORUS   FASCIATUS 

leaf  that  we  might  see  her 

method  of  work.  She  went  on  for  ten  minutes  without 
noticing  the  change,  and  then,  without  any  circling, 
flew  off  to  visit  her  spider.  When  she  tried  to  return 
to  her  hole  it  was  evident  that  some  landmark  was 
missing.  Again  and  again  she  zigzagged  from  the 
spider  to  the  nesting-place,  going  by  a  regular  path 
among  the  vines  from  leaf  to  leaf  and  from  blossom 
to  blossom,  but  when  she  reached  the  spot  she  did  not 
81 


WASPS,    SOCIAL   AND    SOLITARY 

recognize  it.  At  last  we  laid  the  leaf  back  in  its  place 
over  the  opening,  when  she  at  once  went  in  and  resumed 
her  work,  keeping  at  it  steadily  for  ten  minutes  longer. 
At  this  point  she  suddenly  reversed  her  operations  and 
began  to  fill  the  hole  that  she  had  made,  kicking  in  the 
earth  until  the  entrance  was  hidden.  She  then  glanced 
at  the  spider,  selected  a  new  place,  and  began  to  dig 
again.  Surprisingly  large  pellets  of  earth  were  carried 
out,  backward,  and  loose  dirt  was  kicked  under  the 
body  by  the  first  legs.  At  the  end  of  two  or  three  min- 
utes she  paused  and  remained  perfectly  still  for  a  time, 
considering  the  situation.  Her  conclusion  was  adverse 
to  the  locality,  for  she  soon  filled  in  the  hole,  looked  once 
more  at  the  spider,  and  started  a  third  nest  in  a  new 
place.  This  in  turn  was  soon  abandoned,  as  was  also  a 
fourth.  The  fifth  beginning  was  made  under  a  leaf  that 
lay  close  to  the  ground,  so  that  we  could  not  see  her  at 
all.  Fasciatus !  had  we  had  the  naming  of  her  she 
should  have  gone  down  the  ages  as  exasperans!  We  had 
now  watched  her  for  an  hour  in  the  intense  heat ;  the 
bell  for  the  noonday  meal  had  sounded,  hunger  and 
thirst  had  descended  upon  us,  and  most  devoutly  did 
we  hope  that  she  was  suited  at  last,  but  no  —  after 
twenty  minutes'  work  this  place  also  was  abandoned, 
and  a  sixth  nest  started.  This,  however,  was  the  final 
82 


SEVERAL   LITTLE   WASPS 

choice,  and  after  forty-five  minutes  spent  in  digging,  it 
was  completed.  As  the  spider  was  brought  toward  the 
nest  it  was  left  again  and  again  while  the  nervous  little 
wasp  flew  to  the  hole,  went  in,  examined,  and  came  out 
again.  At  last  she  backed  in,  caught  the  spider  by  the 
abdomen,  and  dragged  it  down.  It  was  too  big  —  the 
head  stuck  in  the  hole;  but  she  pulled  from  below  while 
we  pushed  gently  from  above,  and  it  slowly  disappeared. 
When  she  came  out  we  opened  the  nest  and  took  the 
spider.  The  egg  was  fastened  to  the  middle  of  the  left 
side  of  the  abdomen.  This  one,  as  was  also  the  case  with 
a  second  and  third  afterward  taken  from  fasciatus,  was 
much  less  affected  by  the  poison  than  is  usual  among  the 
victims  of  solitary  wasps,  moving  from  the  time  it  was 
taken,  without  any  stimulation,  and  improving  rapidly 
from  day  to  day.  Our  second  spider  appeared  to  be 
blind,  and  died  upon  the  sixteenth  day,  while  the  third 
had  entirely  recovered  by  the  seventeenth  day  after  it 
was  stung,  and  was  released.  Fasciatus,  then,  probably 
depends  upon  packing  her  victim  in  tightly  to  keep  it 
quiet. 

It  was  three  days  and  a  half  before  the  egg  that  we 
had  taken  hatched.  The  larva  developed  rapidly,  retain- 
ing its  hold  at  the  spot  to  which  the  mother  had  fastened 
it.  The  spider  remained  alive  for  six  days,  and  the  larva 
83 


WASPS,    SOCIAL   AND    SOLITARY 

continued  to  grow  for  two  days  longer,  when  it  died 
also,  being  at  the  time  about  two  thirds  grown.  We  had 
great  trouble  in  protecting  our  growing  larvae  from  the 
inroads  of  fungi,  and  this  was  one  of  the  many  that  per- 
ished from  that  cause. 

The  next  example  of  fasciatus  that  came  under  our 
notice  was  a  remarkable  contrast  to  the  one  that  we 
have  just  described,  being  as  slow  and  dignified  as  the 
other  was  nervous  and  hurried.  She  cnose  a  place  and 
kept  to  it,  her  steady  labor  being  interrupted  only  by 
occasional  visits  to  the  spider;  but  it  took  her  fifty  min- 
utes to  complete  the  nest.  When  finished  it  was  a  small 
gallery  running  down  obliquely  for  an  inch  and  a  half 
into  the  ground. 

The  only  habit  that  this  species  can  claim  as  peculiar 
to  itself  is  the  strange  and  useless  one  of  filling  up  the 
partly  made  nests  that  it  is  about  to  abandon.  We  have 
never  seen  the  sense  of  order  carried  to  so  high  a  point 
in  any  other  wasp. 

On  a  hillside  near  our  cottage  stands  a  log  cabin, 
deserted  and  untenanted  save  for  small  creatures  of  the 
wild,  which,  though  a  favorite  spot  with  wood-boring 
wasps,  is  an  unprofitable  place  for  study  because  of  the 
difficulty  of  cutting  out  their  nests  without  destroying 
property.  One  day  in  early  July,  however,  when  we 
84 


WASP    HOMES    IN    THE    LOG    CABIN 


r 


SEVERAL   LITTLE   WASPS 

were  in  the  full  fervor  of  hunting  and  longed  to  utilize 
every  moment,  the  wasps  in  our  garden  seemed  to  have 
resolved  that  enjoyment  and  enjoyment  only  was  their 
destined  end  and  way,  and  became  so  exasperatingly 
idle  that  in  disgust  we  turned  to  the  cabin.  For  half  an 
hour  we  saw  nothing  more  exciting  than  a  Trypoxylon 
immuring  her  victims  and  a  Pompilus  hunting  spiders 
under  the  eaves,  but  at  the  end  of  that  time  Passolocus 
annulatus,  a  tiny  wasp  new  to  us,  came  flying  quietly 
along  and  entered  one  of  the  holes  with  which  the  ends  of 
the  logs  were  riddled.  She  was  carrying  an  aphis  in  her 
mandibles,  and  when  this  was  duly  stored  she  reap- 
peared and  flew  away.  She  had  probably  just  renewed 
her  work  after  a  spell  of  rest,  since  from  this  time  on  for 
nearly  an  hour  she  came  back  regularly  every  four  or  five 
minutes.  She  nearly  always  alighted  on  a  blade  of  grass 
before  going  into  the  nest,  but  did  not  appear  to  be 
malaxing  her  prey.  Presently  another  stage  in  the  game 
was  reached.  She  no  longer  brought  aphides,  but  little 
pellets  of  mud  with  which  she  plastered  up  the  opening. 
After  she  had  finished  this  task  and  departed,  we  care- 
fully chiseled  into  the  log  and  laid  bare  the  nest.  The 
tunnel  ran  in  for  about  three  inches,  and  ended  in  three 
pockets  which  were  well  stocked  with  dead  aphides, 
there  being  fifty-seven  in  all.  The  innermost  cell  con- 
8? 


WASPS,    SOCIAL    AND    SOLITARY 

tained  a  larva,  and  in  the  others  were  eggs,  one  of  which 
hatched  on  the  next  day  and  one  on  the  day  following. 
This  second  one  was  probably  laid  just  before  the  nest 
was  sealed,  giving  forty  hours  for  the  egg  stage;  and  it 
proved  to  be  the  healthiest  of  the  three.  The  others  per- 
ished in  early  infancy;  but  this  one  passed  twelve  days 
in  eating,  not  only  its  own  share  of  provisions,  but  those 
destined  for  the  other  members  of  the  family  as  well, 
and  then  spun  its  cocoon. 

We  afterwards  saw  many  of  these  wasps  working  in 
the  logs  of  the  cabin,  and  noticed  that  they  seemed  to 
have  seasons  of  leisure  alternating  with  spells  of  active 
work,  as  though  when  one  cell  had  been  filled  up  and 
the  egg  laid  they  felt  at  liberty  to  amuse  themselves  for 
a  time  before  beginning  on  another.  When  an  entirely 
new  residence  was  to  be  chosen  they  went  house-hunting 
among  the  old  holes  in  the  logs;  and  whether  they  had  a 
high  standard  of  sanitary  conditions,  or  whether  they 
objected  to  making  extensive  repairs,  a  great  many 
places  were  examined  and  rejected  before  they  settled 
down.  The  choice  once  made,  many  loads  of  pith  were 
carried  out  before  the  little  householder  was  satisfied. 
After  the  new  abode  was  put  to  rights,  the  wasp  would 
pass  a  whole  day  in  rest,  spending  much  of  the  time  in 
looking  out  of  her  doorway  and  perhaps  in  observing 
88 


SEVERAL   LITTLE   WASPS 

the  doings  of  her  neighbors,  but  when  she  began  to  work 
she  was  very  industrious,  and  allowed  nothing  to  inter- 
fere with  her  labors,  paying  no  more  attention  to  us,  no 
matter  how  closely  our  curiosity  led  us  to  interrogate 
her,  than  if  we  had  been  trees  blown  about  by  the 
wind. 

Some  of  the  wasps  dig  deep  into  the  stems  of  bushes 
to  form  galleries  for  their  nests,  but  we  found  one  wise 
genus  that  went  in  only  far  enough  to  make  one  or  two 
cells,  thus  saving  the  trouble  of  carrying  her  cuttings 
thirty  or  forty  centimeters  in  direct  opposition  to  the 
force  of  gravity.  This  was  Odynerus,  whose  nests  we 
found  in  July,  in  blackberry  and  raspberry 
stems.  Our  first  species  was  perennis,  whose 
nests  bear  her  mark  in  the  shape  of  a  pellet 
of  earth  placed  above  each  mud  partition. 
One  of  her  cells  contained  a  wasp  larva  and 
about  sixteen  caterpillars,  nearly  one  third 
of  which  were  dead,  while  the  rest  were  more 
or  less  lively.  They  seemed  to  have  been 
stung  near  the  anterior  part,  as  the  last  three 


or  four  segments  were  jerked  up  violently  NEST  OF 
when  touched.  The  larva  went  on  eating,  PKRENNIS 
and  the  caterpillars  went  on  dying  from  hour  to  hour. 
At  the  end  of  the  eighth  day,  the  baby  wasp  finished 
89 


WASPS,   SOCIAL   AND   SOLITARY 

its  meal,  having  eaten  all  that  had  been  provided  for 
it,  as  well  as  two  dead  caterpillars  from  another 
nest. 

Much  interest  attaches  to  the  way  in  which  Odynerus 
lays  her  egg,  since  instead  of  following  the  common 
fashion  of  fastening  it  to  the  prey  she  suspends  it  by  a 
tiny  filament  of  web  from  the  wall  or  ceiling  of  her  cell. 
Thus  in  O.  reniformis,  nesting  in  the  ground,  it  is  hung 
from  the  ceiling,  a  mass  of  very  imperfectly  paralyzed 
caterpillars  being  collected  below,  and  when  the  larva 
comes  out  the  thread  lengthens  until  the  tiny  jaws  reach 
the  food  supply.  Startle  it  ever  so  slightly  and  the  wasp- 
ling  retreats  by  way  of  its  web,  descending  again  only 
when  everything  is  quiet.  For  twenty-four  hours  it 
retains  this  path  to  safety,  and  then,  growing  bold,  it 
drops  down  and  feeds  at  its  ease. 

We  had  opened  hundreds  of  plant  stems  in  quest  of 
these  suspended  eggs  without  being  so  fortunate  as  to 
find  one,  and  were  therefore  much  pleased  when  our 
kind  friend,  Dr.  Sigmund  Graenicher,  whose  interest 
in  bees  keeps  him  in  touch  with  out-of-door  happenings, 
and  who  has  given  us  much  valuable  help,  brought  us 
two  stalks,  one  of  which  had  in  it  a  nest  of  O.  conformis, 
while  the  other  contained  two  freshly  provisioned  cells 
of  O.  anormis.  In  all  three  the  egg  had  been  hung  from 
90 


SEVERAL    LITTLE   WASPS 

the  side  of  the  cell  about  one  third  of  the  way  down,  and 
in  the  nest  of  conformis,  from  which  all  but  one  of  the 
caterpillars  had  fallen,  it  hung  loose  against  the  wall. 
In  the  other  nests  the  lower  part  was  packed 
tightly  with  sixteen  small  larvae,  upon  which 
lay  the  egg,  supported  in  a  horizontal  posi- 
tion, although  attached  to  the  side  wall  ex- 
actly as  in  conformis,  and  above  were  eight 
more  caterpillars,  the  whole  forming  a  com- 
pact mass  shut  in  by  the  usual  partition  of 
mud.    So  closely  were  they  crammed  in  that 
after  counting  them  we  were  unable  to  get 
them  all  back  again,  and  although  motion- 
less in  their  narrow  quarters  they  became      NEST  OF 

ANORM1S 

quite  active  when  relieved  from  pressure. 
This  is  an  entirely  different  arrangement  from  that  of 
O.  reniformis,  and  since  the  larva  is  in  contact  with  the 
caterpillars  from  the  moment  of  hatching  the  manner 
of  the  egg-laying  has  no  significance  in  relation  to  the 
safety  of  the  young. 

Conformis  hatched  on  the  morning  after  we  received 
it,  sloughing  off  the  skin  of  the  egg,  but  remaining  at- 
tached to  it,  and  thus  doubling  the  length  of  the  thread 
by  which  it  hung.  The  caterpillar  was  slightly  separated 
from  it,  and  it  seemed  to  have  no  notion  of  feeling  about 


WASPS,    SOCIAL   AND    SOLITARY 

for  its  food,  eating  nothing  for  twenty-four  hours,  but 
growing  and  developing  nevertheless.  We  now  piled 
up  some  caterpillars  in  contact  with  it,  and  it  began  to 
eat,  but  after  its  own  caterpillar  and  as  many  as  we  dared 
take  from  anormis  were  gone  it  stubbornly  refused  to 
take  soft,  tender  little  spiders,  or  caterpillars  out  of  our 
garden;  and  it  perished,  a  victim  to  prejudice. 

The  two  eggs  of  anormis  were  probably  laid  within  a 
few  hours  of  each  other,  since  they  had  both  hatched 
on  the  morning  of  the  third  day,  and  had  broken  from 
their  attachment,  beginning  to  eat  at  once.  They  co- 
cooned  on  the  fifth  day  after  hatching. 

We  had  long  wished  to  find  a  nest  of  O.  capra,  and 
early  in  September  fortune  favored  us.  A  neighbor  of 
ours  keeps  a  large  tin  horn  hanging  under  the  porch. 
One  day  when  she  wished  to  use  it,  no  amount  of  blow- 
ing would  bring  forth  a  sound;  and  when  she  unscrewed 
the  mouthpiece  to  investigate  the  matter,  out  tumbled 
several  small  green  caterpillars  and  a  quantity  of  dry 
mud.  When  we  heard  of  this  incident  we  begged  that  if 
it  should  be  repeated  the  nest  and  its  contents  might  be 
saved  for  us;  and  on  the  second  of  September  we  re- 
ceived the  mouthpiece  of  the  horn  with  a  message  to 
the  effect  that  a  wasp  had  been  working  at  it  for  some 
days.  Examination  showed  that  there  were  three  cells, 
92 


SEVERAL   LITTLE   WASPS 

each  containing  a  larva  and  a  supply  of  caterpillars,  of 
which  there  were  ten  in  the  cell  most  lately  formed,  and 
only  one  left  uneaten  in  the  oldest.  The  caterpillars,  all 
of  them  being  alive,  together  with  the  wasp  larvae,  were 
transferred  to  a  place  in  which  they  could  be  conven- 
iently watched.  None  of  the  caterpillars  died  until  they 
were  attacked.  The  larvae  ate  all  the  food  that  was  pro- 
vided, the  oldest  one  cocooning  on  the  fourth,  and  the 
second  one  on  the  seventh  of  September.  Of  the  third, 
we  have  no  record,  excepting  that  the  caterpillars  had 
all  been  eaten  on  September  eighth. 

We  happened  to  be  passing  through  our  neighbor's 
grounds  at  nine  o'clock  on  the  morning  of  September 
fifth,  and  calling  to  ask  whether  there  had  been  any 
more  visits  from  the  wasp,  we  learned  that  capra  had 
been  seen  making  a  mud  partition  in  the  horn  on  the 
day  before.  While  we  were  speaking  she  arrived  and 
entered  the  mouthpiece,  where  she  remained  for  about 
ten  minutes.  When  she  departed  we  found  that  she  had 
laid  her  egg,  which  we  carried  away  with  us,  wishing 
to  determine  the  length  of  the  egg  stage.  This  proved 
to  be  longer  than  that  of  any  wasp  that  we  had  hereto- 
fore known,  for  not  until  the  morning  of  September 
ninth  did  the  larva  make  its  appearance,  the  egg  skin 
bursting  and  leaving  its  tenant  free  to  crawl  away.  In 
93 


WASPS,    SOCIAL   AND    SOLITARY 

other  genera  the  egg  changes  into  a  larva  imperceptibly, 
there  being  no  sloughing  off  of  the  skin. 

Capra,  then,  first  finds  a  suitable  crevice,  and  builds  a 
partition  across  the  inner  end,  the  earth  being  scratched 
up  from  some  dry,  bare  spot,  and  moistened  in  her 
mouth.  Before  gathering  the  ten  or  twelve  small  cater- 
pillars that  are  to  provision  the  cell,  she  lays  her  egg; 
and  although  we  could  not  be  sure,  we  thought  that  in 
this  case  as  in  the  others  it  was  suspended. 

Unless  the  cell  is  tightly  packed  at  the  beginning, 
capra  certainly  needs  the  filament,  for  her  caterpillars 
were  so  far  from  being  reduced  to  a  state  of  decent  im- 
mobility that  we  had  to  press  wads  of  cotton  into  the 
tubes  in  which  they  were  kept  to  prevent  them  from 
wriggling  out  of  the  way  of  the  larva.  None  of  our 
larvae,  not  even  the  one-day-old  ones,  were  injured  by 
their  activity;  but  had  the  egg  been  left  to  its  fate  among 
them  it  might  have  perished. 

Later  in  September  we  found  O.  vagus  bringing  pel- 
lets from  a  sharp-edged  hole  in  the  ground.  Her  method 
was  to  carry  each  load  on  the  wing  to  a  distance  of  ten 
or  twelve  inches,  where  it  was  dropped  without  the  lively 
fling  with  which  Ammophila  discards  her  lump  of  dirt. 
The  red  end  of  a  match  stuck  into  the  ground  two 
inches  away  proved  very  disquieting  to  the  dainty  little 
94 


SEVERAL    LITTLE    WASPS 

wasp.  These  colored  matches  were  a  great  convenience 
in  marking  nests,  and  as  we  were  using  them  constantly, 
we  did  not  guess,  for  a  time,  what  the  trouble  was.  For 
half  an  hour  she  went  and  came,  circling  about,  alight- 
ing upon  plants,  and  seeming  entirely  absorbed  in 
examining  them  with  the  minutest  care,  even  alighting 
upon  our  hands  with  most  engaging  friendliness,  but 
pretending  all  the  time  that  the  nest  was  naught  to  her. 
When  the  offending  object  was  removed  she  hurried 
in  at  once  and  resumed  her  work.  The  storing  was  not 
begun  until  the  next  morning,  when  she  took  in  six 
caterpillars  of  very  different  sizes,  at  intervals  of  from 
ten  to  twenty  minutes,  and  then  filled  the  hole.  We 
hoped  to  find  the  little  chamber  arranged  as  in  reni- 
formis,  but  had  not  skill  enough  to  excavate  in  such  a 
way  as  to  show  the  internal  plan.  It  is  remarkable  that 
this  genus,  with  only  one  set  of  tools  for  all  its  species, 
has  worked  out  such  different  styles  of  architecture,  the 
ground  nests  bearing  no  resemblance  to  those  cut  out 
of  woody  stalks ;  and  its  flexibility  is  shown  in  the  use 
of  empty  snail  shells  by  a  foreign  species,  as  well  as 
by  capra's  habit  of  partitioning  off  convenient  crevices 
found  ready  made. 

The  prettiest  nests  that  we  have  seen  in  stems  are 
those  of   Plenoculus   peckhamii,   which   separates   its 
95 


WASPS,    SOCIAL    AND    SOLITARY 

cells,  not  by  solid  partitions,  but  by  numerous  granules 
of  earth,  which  are  used  by  the  larvae  for  forming  the 
case  of  the  cocoon.  One  raspberry  stalk  that  we  opened 
had  at  the  bottom  six  of  these  mud  cocoons,  and  above 
these  three  larvae  eating,  each  in  its  own  compartment, 
the  provision  in  this  case  consisting  of  immature  bugs 
of  the  genus  Pamera.  Sometimes  the  stalk  which  is 
being  filled  by  Plenoculus  attracts  the  fancy  of  a  bee  or 
of  another  wasp,  as  is  shown  by  the  upper  cells  being 
filled  by  Osmia  or  Crabro,  or  sometimes  Plenoculus 
builds  above  the  bee  cells.  When  a  number  of  wasp 
eggs  are  placed  in  a  plant  stem,  the  last  one  laid  is  the 
first  to  hatch.  The  different  habits  of  the  Hymenoptera 
in  this  respect  are  very  interesting.  In  the  case  of  Cera- 
tina  dupla,  the  small  carpenter  bee,  the  egg  first  laid 
hatches  first,  those  above  following  in  regular  order. 
The  lower  ones  wait  patiently  in  their  cells  until  the  one 
in  the  top  cell  has  matured,  and  then  they  all  come  out 
at  once.  When  two  species  occupy  the  same  stalk,  the 
lack  of  adjustment  probably  results  in  the  destruction 
of  those  lower  down,  excepting  in  the  case  of  the  cuckoo 
flies,  which  have  acquired  the  habit  of  gnawing  their 
way  out  at  the  side  of  the  stem. 


Chapter  V 

CRABRO 

THE  highest  point  of  the  island  is  crowned  by  a 
great  group  of  linden  trees ;  and  one  day  their 
perfume,  carried  by  the  wind  far  over  field  and  wood, 
was  calling  everything  that  had  wings  to  gather  the  rich- 
est of  all  the  gifts  that  July  can  offer.  We,  too,  were 
drawn  to  the  spot,  and  found  the  great  blossoming  domes 
thrilling  and  vibrating  with  life.  For  miles  around,  the 
bees,  wasps,  and  butterflies  had  gathered  to  the  feast; 
and  we  seemed  to  touch  the  high-tide  of  the  year  in  the 
scent  of  the  flowers,  the  humming  throng  of  happy 
creatures,  and  the  vision  of  it  all  against  the  summer 
sky. 

Below,  in  a  great  root  that  had  pushed  above  ground, 
five  little  wasps,  by  name  sexmaculatus,  of  the  worthy 
but  unimaginative  genus  Crabro,  resisting  the  intoxica- 
tion of  the  linden  flowers,  were  sawing  and  cutting  in 
the  most  humdrum  and  practical  manner.  One  of 
them,  presumably  the  earliest  riser,  was  well  down  in 
the  root,  and  came  backing  up  once  in  a  while,  pushing 
97 


WASPS,    SOCIAL   AND    SOLITARY 

a  lot  of  wood  dust  out  of  the  hole.  This  was  spread  out 
by  means  of  legs  and  mandibles,  and  was  then  blown 
away  by  the  fanning  wings  of  the  little  worker,  who  cir- 
cled about  just  above  the  ground  until  the  last  grain  had 
disappeared.  Here  was  another  way  of  protecting  the 
home.  The  fresh  dust  might  attract  the  attention  of 
some  cuckoo-like  insect  who  would  lay  her  egg  within ; 
and  therefore  it  was  dispersed,  just  as  Ammophila  car- 
ried out  her  pellet  and  flung  it  to  a  distance,  and  Sphex 
spread  evenly  over  the  ground  the  mass  of  earth  that 
she  carried  from  her  hole. 

After  this  series  of  actions  had  been  repeated  several 
times  the  wasp  flew  away  to  hunt.  We  afterward  found 
that  she  had  finished  the  third  in  a  set  of  cells  leading 
from  a  main  gallery.  On  her  return  we  delayed  her  to 
see  what  she  was  carrying.  She  showed  no  fear,  but 
alighted  close  by,  and  while  she  was  trying  to  transfer 
to  the  third  pair  of  legs  the  fly  that  she  was  clasping  with 
the  second  pair,  it  escaped  and  flew  gayly  away.  Flies 
are  plenty,  however,  and  she  soon  had  another  which 
she  was  permitted  to  store ;  and  from  that  time  she 
worked  busily  until  we  left  her  at  noon.  It  took  her 
from  two  to  ten  minutes  to  catch  her  fly,  and  at  each 
return  two  or  three  minutes  were  spent  in  the  nest.  On 
opening  her  tunnel  some  days  later,  we  found  within 
98 


3w>  rf*:>dt!^'4i"  "'<  vAv*.  Ji«si5aK5«W  .• 


CRABRO 

not  only  flies,  but  long-bodied  gnats,  and  all  of  them 
seemed  to  have  been  brought  home  uninjured.  When 
the  freshest  cell  was  opened  some  flew  away,  others 
were  walking  about,  and  all  were  lively.  The  wasp  egg 
was  laid  on  the  under  side  of  the  neck ;  and  although 
we  could  not  be  certain  of  the  exact  time  of  laying  we 
thought  it  hatched  at  the  end  of  thirty-six  hours.  From 
ten  to  sixteen  flies  were  provided  for  each  larva. 

A  month  later  we  found  Crabro  lentus  nesting  in  the 
ground.  Her  tunnel  ran  down  obliquely  for  six  and  one 
half  centimeters,  and  had  an  enlargement  at  the  end. 
Two  bugs  and  a  fly  were  in  the  nest,  when  we  opened  it 
before  the  provision  was  completed.  To  find  sexmacu- 
latus  taking  both  flies  and  gnats  was  surprising,  so  rigid 
are  the  family  traditions  of  the  wasps;  still,  she  might 
feel  that  so  long  as  she  drew  the  line  at  Diptera  she  was 
all  right.  But  to  believe  that  one  wasp,  a  Crabro,  too, 
with  all  the  marks  of  conservatism  about  her,  would 
take  such  diverse  things  as  bugs  and  flies,  is  almost  too 
much  to  believe.  It  is  true  that  Crabro  wesmaeli  is  said 
to  use  both  flies  and  bugs;1  but  some  accident  may 
have  led  to  this  supposition,  and  stronger  evidence  is 
needed  to  prove  that  there  is  variability  in  so  deeply 
seated  an  instinct. 

1  Sharp,  Insects,  page  130. 
101 


WASPS,    SOCIAL    AND    SOLITARY 

The  Crabro  wasps  all  have  pleasant  ideas  as  to  where 
they  want  to  live,  but  interruptus  excels  in  the  choice 
of  a  dwelling  place.  We  lately  found  ten  or  twelve  of 
them  in  Milwaukee,  nesting  in  an  old  log  on  the  shore 
of  Lake  Michigan,  and  when  they  opened  their  doors 
in  the  morning  they  had  before  them  the  splendor  of  the 
great  bay;  but  calm  in  the  midst  of  the  glory  they  never 
paused  on  the  threshold,  as  Cerceris  would  have  done, 
to  take  a  look  at  the  world  before  going  to  work.  One 
morning  the  earliest  riser  in  our  little  colony  was  begin- 
ning the  day  at  half  past  nine.  Of  good  size  for  a  Crabro, 
with  a  square  determined-looking  head  and  very  direct 
and  business-like  manners,  she  proceeded  to  cut  out 
a  new  chamber  for  provisioning.  These  chambers  are 
nothing  more  than  enlargements  of  the  long  gallery, 
such  as  are  made  in  stems  by  related  species.  At  ten 
o'clock  she  departed  on  a  hunting  excursion  among  the 
bushes  on  the  bank  above  us,  and  came  back  in  eight 
minutes,  carrying,  much  to  our  surprise,  a  white- winged 
moth,  which  was  clasped  under  the  body  by  the  second 
and  third  pairs  of  legs,  and  was  passed  back  to  the  third 
pair  as  she  alighted  before  entering.  A  moth  is  an  inno- 
vation, a  delicacy  new  to  the  accepted  idea  of  what  a 
Crabro  larder,  accustomed  to  Diptera,  should  contain. 
A  moment  later  she  was  off  again,  but  this  time  did  not 
102 


CRABRO    AND    HER    WHITE   MOTHS 


CRABRO 

succeed  so  quickly,  coming  back  twice  empty-handed 
for  brief  visits,  and  bringing  in  a  load  at  the  end  of  half 
an  hour.  It  took  six  moths  to  provision  the  cell,  and  as 
the  number  neared  completion  her  interest  and  energy 
seemed  to  wax  greater,  the  hunting  intervals  shortening 
to  five,  and  even  to  two  minutes.  We  found  afterwards 
that  some  of  the  moths  were  alive  and  some  dead,  and 
that  she  packed  them  lengthwise,  one  after  another, 
into  the  closely  fitting  chamber.  At  a  little  before  eleven 
o'clock  the  cell  was  filled,  and  the  wasp  retired  from 
sight,  closing  the  door  behind  her.  We  thought  that  she 
was  resting,  but  presently  the  protrusion  of  wood  dust 
showed  that  she  was  enlarging  her  house,  and  an  hour 
later  she  came  out  and  began  to  hunt  again.  By  this 
time  half  a  dozen  were  working.  Before  leaving  for  the 
first  time  in  the  morning  each  one  made  a  thorough 
study  of  the  place,  and  on  returning  they  entered  their 
own  doors,  which  were  standing  open,  without  hesita- 
tion, the  long  white  wings  of  the  moths  trailing  behind 
them.  Four  species  were  represented  in  the  nests  that 
we  opened. 

Many  species  of  Crabro  make  their  nests  in  the  stems 
of  plants,  and  among  these  is  stirpicola,  which  is  seen 
in  numbers,  through  the  middle  of  July,  flying  about  in 
a  leisurely  way,  though  it  is  only  toward  the  end  of  the 


WASPS,    SOCIAL    AND    SOLITARY 

month,  or  in  the  early  days  of  August,  that  they  settle 
down  to  the  work  of  making  their  homes.  On  the  after- 
noon of  July  twenty-seventh,  after  some  very  lively 
work  in  the  heat  of  the  day,  we  walked  down  to  the 
berry  garden  at  half  past  five 
o'clock,  rather  to  rest  our- 
selves than  with  the  thought 
of  undertaking  any  thing  new; 
but  a  wasp -hunter  cannot 
afford  to  choose  his  own 
hours,  and  we  thankfully 

CRABRO   STIRP1COLA 

accepted  the  sending  of  for- 
tune when  we  came  upon  a  stirpicola  busy  at  work  in 
digging  out  her  nest.  She  had  only  begun  to  excavate, 
and  had  reached  a  length  just  equal  to  that  of  her  own 
body.  Her  manners  were  an  agreeable  contrast  to  those 
of  the  wasps  that  we  had  been  watching  through  the 
day.  The  feverish  excitement  of  their  ways  seemed 
quite  in  keeping  with  the  burning  heat  of  noon,  while 
Crabro's  slow  and  gentle  movements  harmonized  per- 
fectly with  the  long  shadows  of  evening.  To  fully  appre- 
ciate the  difference  between  Pompilus  or  Ammophila 
and  Crabro  it  is  necessary  to  see  them  at  work.  The 
one  is  the  embodiment  of  all  that  is  restless,  vying 
with  the  humming-birds  in  swiftness  and  energy,  while 
106 


CRABRO 


the  other  is  calm,  quiet,  and  stately  in  all  that  she 
does. 

Some  ten  feet  away  was  a  second  stirpicola,  and  this 
one,  to  judge  from  the  depth  to  which  she 
had  penetrated,  must  have  been  at  work  for 
about  two  hours.  We  watched  them  both, 
and  saw  them  bring  up  load  after  load  of 
pith.  They  bit  out  the  pellets  with  their 
mandibles,  and  passed  them  back  between 
the  legs  and  under  the  body  until  a  quantity 
had  accumulated  above  the  tip  of  the  abdo- 
men. They  then  walked  backward  up  the 
stem,  and  thus  pushed  out  the  mass  as  they 
came  to  the  top.  Often  they  used  the  hind 
legs  to  assist  in  getting  it  out  of  the  way, 
sometimes  kicking  it  to  a  little  distance.  Once 
in  every  two  or  three  trips  they  would  come 
out  far  enough  to  expose  part  of  the  thorax. 
They  appeared  and  disappeared  with  the 
regularity  of  a  machine,  never  stopping  to 
rest. 

We  remained  with  them  until  seven  o'clock, 
when  we  placed  a  long  bottle  over  each  stem 
in  such  a  way  that  while  it  did  not  interfere  with  the 
work  of  the  wasp,  it  caught  the  chips  of  pith  as  they 
107 


BOTTLE  ON 
STEM  TO 
MEASURE 
WORK  OF 
CRABRO 


WASPS,    SOCIAL   AND    SOLITARY 

fell  out.  At  the  end  of  an  hour  we  noted  the  amount 
of  accumulation  in  the  tube,  and  thus  had  a  measure 
of  their  rate  of  work.  The  drawing  gives  an  idea  of  the 
arrangement  of  the  tube  on  the  stem.  When  we  left 
them  they  were  still  digging  and  delving. 

At  half  past  nine  we  took  a  lantern  and  went  down 
to  visit  our  charges.  We  expected  to  find  them  at  rest, 
and  asleep;  but  on  the  contrary  they  were  working  as 
busily  as  ever,  and  upon  examining  the  measuring 
glasses  we  found  that  they  had  not  paused  since  we 
left  them.  We  measured  the  depth  of  the  debris  in  the 
bottles,  and  then  emptied  them. 

At  four  o'clock  on  the  next  morning  we  went  to  the 
garden,  and  were  much  surprised  to  find  that  the  two 
wasps  had  worked  without  intermission  throughout 
the  night.  Indeed  they  seemed  to  have  shortened  a 
little  the  time  that  it  took  to  make  a  round  trip  down 
the  gallery  and  up  to  the  opening  again,  since  there 
was  more  pith  in  the  bottles  than  we  could  have  ex- 
pected if  they  had  worked  at  only  their  former  rate. 
Neither  the  coolness  of  the  air  nor  the  darkness  of  the 
night  had  made  the  slightest  difference  to  them.  After 
watching  them  a  few  minutes,  and  marveling  at  their 
powers  of  endurance,  we  cleared  out  the  tubes  and 
returned  to  bed.  At  half  past  eight  we  found  them  still 
108 


CRABRO 

I  at  work.  Unlike  us,  they  had  taken  no  morning  nap, 
I  but  had  gone  on  with  their  tunneling  in  their  usual 
steady  way. 

From  this  time  their  ways  diverged,  and  they  must  be 
described  separately.  At  nine  o'clock  the  one  that  we 
had  first  seen  came  up  to  the  opening,  walking  head 
first,  and  flew  off,  remaining  away  seven  minutes.  When 
she  returned  she  at  once  resumed  her  work,  and  kept 
at  it  without  a  pause  until  two  in  the  afternoon.  At  this 
hour  she  went  away,  and  we  never  saw  her  again.  We 
suppose  that  she  was  killed,  for  it  seems  improbable 
that  so  faithful  a  creature  could  have  deserted  her  half- 
finished  home.  Pompilus  quinquenotatus  often  deserted 
a  partly  finished  nest  for  some  more  enticing  spot,  and 
Sphex  started  several  excavations  before  making  a  final 
choice;  but  we  cannot  believe  that  there  was  anything 
fickle  about  Crabro. 

The  second  wasp  came  up  head  first  to  the  entrance 
of  her  hole  at  two  minutes  after  nine,  as  though  she 
had  been  influenced,  in  some  subtle  way,  by  her  neigh- 
bor's example;  but  after  looking  about  for  a  moment 
she  went  back.  She  repeated  this  observation  several 
times,  and  finally,  at  twenty-five  minutes  after  nine, 
came  out  and  flew  to  a  leaf  near  by.  Then  she  cir- 
cled around,  alighting  a  number  of  times,  and  at  last 
109 


WASPS,    SOCIAL   AND    SOLITARY 

departed.  Her  stay  was  brief,  for  at  just  thirty-five 
minutes  after  nine  she  returned,  and  at  once  settled 
down  to  her  work. 

We  now  began  to  make  notes  as  to  the  length  of  time 
that  it  took  her  to  go  down  and  bring  back  her  load.  We 
timed  her  again  and  again,  and  found  that  she  was 
remarkably  regular,  each  of  her  trips  occupying  from 
forty-five  to  fifty  seconds. 

All  that  day  we  kept  her  under  strict  surveillance,  and 
never  once  did  she  suspend  her  operations  either  for  rest 
or  refreshment.  Late  in  the  afternoon,  while  we  sat 
watching  her  as  she  appeared  and  disappeared  with 
almost  the  regularity  of  clockwork,  we  found  it  difficult 
to  realize  that  the  patient  little  creature  had  been  at 
work  for  more  than  twenty-four  hours,  with  only  one 
brief  intermission.  Without  hurry  or  flurry  she  kept  at 
her  task,  reminding  us,  in  her  business-like  ways,  of  the 
social  wasps  of  the  genus  Vespa.  When  we  left  her, 
at  dusk,  we  attached  the  recording  tube  to  the  stem, 
and  at  ten  o'clock  in  the  evening  we  found  that  she 
had  not  stopped  working.  We  emptied  the  glass,  and 
left  her. 

At  seven  o'clock  in  the  morning  of  July  twenty-ninth 
we  paid  her  a  visit,  and  could  scarcely  believe  the  testi- 
mony of  our  senses  when  we  saw  that  the  record  was  one 


CRABRO 

of  unceasing  toil  through  the  long  hours  of  the  second 
night.  We  began  to  wonder  if  she  would  ever  finish  her 
task.  Wonderful  though  she  was,  we  had  grown  a  little 
weary  of  our  long  session  of  watching.  We  had  been 
glad  that  she  worked  through  the  first  night;  it  was 
creditable  to  her  and  interesting  to  us,  and  we  admired 
her  even  more  for  sticking  to  it  through  the  second,  but 
when  it  looked  as  though  we  might  have  to  remain  by 
her  side  through  another  long  day,  watching  an  endless 
series  of  loads  as  they  were  carried  out,  we  confess  that 
we  thought  she  was  rather  overdoing  it.  Gradually, 
however,  she  slowed  up  her  work,  taking  two  or  three 
minutes  to  make  a  journey  down  and  up.  At  last,  at  just 
nine  o'clock,  her  head  appeared  at  the  top  of  the  stalk, 
and  after  a  slight  hesitation  she  flew  away.  The  nest  was 
completed. 

We  have  studied  wasps  for  a  number  of  years,  and  we 
feel  that  we  are  on  terms  of  more  or  less  intimacy  with 
many  of  the  species,  but  never  before  have  we  known 
one  to  work  after  day  was  done.  We  have  often  gone 
out  with  a  lantern  at  bedtime  for  a  tour  of  inspection 
among  our  nests,  and  have  always  found  the  inhabitants 
quiet  and  presumably  asleep.  The  social  wasps  are  very 
industrious,  but  during  the  hot  nights  of  July  they  are 
to  be  seen  clustered  together  on  the  outside  of  their  paper 


WASPS,    SOCIAL   AND    SOLITARY 

nests  in  deep  repose ;  and  although  the  Vespa  wasps  that 
nest  in  the  ground  sometimes  come  home  late  in  the  twi- 
light, we  have  never  seen  them  work  after  it  was  really 
dark.  Polistes  fusca  may  be  said  to  share  our  cottage, 
so  thickly  does  she  hang  her  combs  under  the  shelter  of 
our  porches,  and  from  observations  taken  at  all  hours 
we  know  that  she  is  quiet  through  the  night.  Sir  John 
Lubbock,  in  "Ants,  Bees,  and  Wasps,"  speaks  of  the 
great  industry  of  wasps.  He  has  known  them  to  work 
from  early  morning  until  dusk  without  any  interval  for 
rest  or  refreshment;  but  here  was  our  little  Crabro 
toiling  from  three  in  the  afternoon  of  July  twenty- 
seventh,  through  that  night  and  the  day  and  night  fol- 
lowing until  nine  o'clock  on  the  morning  of  the  twenty- 
ninth,  —  a  period  of  forty-two  consecutive  hours  with 
one  intermission  of  ten  minutes  on  the  morning  of  the 
twenty-eighth.  Surely  she  takes  the  palm  for  industry, 
not  only  from  other  wasps,  but  from  the  ant  and  the  bee 
as  well. 

The  nest  was  completed,  but  the  work  of  storing  it 
remained  to  be  done.  The  wasp  flew  away  at  nine 
o'clock,  and  ten  minutes  later  came  back  with  some- 
thing, we  knew  not  what,  for  she  dropped  into  her  hole 
so  quickly  that  she  was  out  of  sight  almost  before  we 
knew  she  was  there.  Two  minutes  later  she  came  up, 


CRABRO 


and  was  off  again.  This  time  she  was  gone  twelve  min- 
utes, and  when  she  returned  we  were  again  baffled  in 
our  effort  to  see  what  she  was  carrying.  When  she  came 
out  she  alighted  upon  a  leaf  and  attended  to  her  toilet, 
cleaning  both  body  and  wings  by  rubbing  them  off  with 
her  hind  legs,  and  from  this  time  on  she  never  started  on 
a  hunting  expedition  without  paying 
this  attention  to  her  personal  ap- 
pearance. On  her  third  trip  she  was 
gone  twenty  minutes,  coming  back 
with  a  small  fly;  and  before  we  left 
her  at  ten  o'clock,  she  had  stored  six 
more.  When  we  came  back  at  half 
past  two  in  the  afternoon  she  was 
working,  and  she  kept  up  her  go- 
ings and  comings  until  four  o'clock, 
when  she  suspended  operations  for 
the  day.  On  the  next  morning  we 
were  called  away,  and  know  nothing 
of  what  she  did,  but  on  the  follow- 
ing day,  Thursday,  we  resumed  our 
observations.  She  worked  hard  all  the  morning,  but 
in  the  afternoon  her  trips  were  few,  and  were  made 
at  long  intervals.  On  Friday  she  worked  from  eight 
to  nine,  when  she  departed,  and  never  returned.  We 


NEST  OF  C.  STIRPICOLA 


WASPS,    SOCIAL    AND    SOLITARY 

watched  for  her,  at  intervals,  all  through  that  day  and 
the  next,  when  we  were  forced  to  conclude  that  our 
faithful  little  worker  had  fallen  a  victim  to  some  bird 
or  beast.  We  did  not  disturb  the  nest  until  four  days 
later,  when  we  cut  the  stalk,  and  examined  it. 

We  found  that  the  tunnel  was  thirty-nine  centimeters 
in  length.  This  was  a  long  distance  for  her  to  excavate, 
and,  all  things  considered,  her  progress  had  been  rapid. 
We  have  opened  a  number  of  stems  that  had  been  stored 
by  this  species,  and  all  the  excavations  were  from  thirty 
to  forty  centimeters  in  length,  the  width  of  the  gallery 
being  about  three  and  one  half  millimeters,  while  on  each 
side  there  was  from  one  to  one  and  one  half  millimeters 
of  pith  that  had  not  been  cut  away.  Of  course  these 
points  varied  with  the  diameter  of  the  stem  and  also 
with  the  size  of  the  worker. 

Our  little  stirpicola  had  stored  one  cell,  had  laid  an 
egg,  and  had  built  a  partition  of  pith  across  the  stem  as 
a  floor  to  the  second  cell,  before  her  untimely  taking  off. 
Had  she  lived,  ten  or  twelve  cells  would  have  been  stored, 
one  above  the  other.  The  completed  cell  contained  a 
larva  and  parts  of  eighteen  flies  of  different  sizes,  four 
species  being  represented.  The  flies  had  all  been  at- 
tacked by  the  larva,  the  abdomens  of  some  and  the  tho- 
races  of  others  having  been  eaten.  The  larva  continued 
114 


AMMOPHILA   SLEEPING    IN    THE    GRASS    (AFTER    BANKS) 


CRABRO 

to  eat  for  two  days,  and  then  spun  its  cocoon.   The  flies 
!  found  in  this  and  in  other  nests  of  stirpicola  were  all 
dead.  All  the  pupae  that  we  kept  wintered  in  the  cocoon 
and  came  out  in  the  spring. 

The  females  of  Crabro,  like  those  of  other  genera, 
seem  to  use  their  galleries  as  sleeping  places,  but  the 
males  stop  at  any  convenient  inn.  We  once  entertained 
one  of  them  for  several  nights  in  a  hole  in  one  of  the 
posts  of  our  cottage  porch.  Other  males,  as  in  Philan- 
thus,  spend  time  and  care  in  digging  a  hole  in  the  ground, 
to  which  they  return  night  after  night.  In  Agenia  the 
female  keeps  one  cell  ahead  of  her  needs,  and  tucks  her- 
self away  in  it  very  comfortably ;  but  the  Pelopaei,  in- 
stead of  making  this  use  of  their  tubes,  congregate  in 
the  evening  where  there  are  convenient  crevices,  and 
make  as  much  fuss  about  getting  settled  as  a  lot  of  Eng- 
lish sparrows.  Mr.  Banks  has  made  a  delightfully  pretty 
as  well  as  interesting  observation  on  the  sleeping  habits 
of  Ammophila.  In  a  corner  of  his  garden  where  the 
grass  grew  long,  dozens  of  these  wasps  arrived  every 
evening,  and  after  a  good  many  changes  in  position, 
fell  sound  asleep,  clinging  to  the  stems  about  one  third 
of  the  way  down.  They  registered  at  this  hotel  between 
seven  and  eight  o'clock,  and  departed  before  five  in  the 
morning.  We  have  seen  a  Pompilus  take  the  greatest 
117 


WASPS,    SOCIAL    AND    SOLITARY 

care  in  selecting  a  sheltered  spot  under  some  leaves, 
where  she  afterward  hung  herself  up,  and  slept  soundly 
until  after  eight  the  next  day;  and  Mr.  Brues  has  found 
companies  of  Priononyx  atrata  passing  the  night  on  the 
stems  of  sweet  clover. 


Chapter  VI 

AN    ISLAND    SETTLEMENT 

OUR  children  often  made  themselves  useful  by  re- 
porting finds  in  the  shape  of  nests,  and  one  day 
they  returned  from  the  island  with  a  wonderful  tale  of 
great  numbers  of  big  wasps  that  were  digging  in  the 
ground.  "I  don't  know  what  they  are,"  said  the  small 
boy,  "  but  they  act  to  me  like  the  maddest  kind  of  hor- 
nets." With  this  attractive  picture  before  us,  we  lost  no 
time  in  going  over  to  the  spot,  where  we  found  a  thriving 
colony  of  Bembex  spinolae.  On  our  approach  they  fell 
upon  us,  "desire  of  blood,  and  rage,  and  lust  of  fight"  in 
their  mien,  and  chased  us  to  a  distance,  but  without  in- 
flicting a  single  wound.  This  temperance  was  not  due  to 
gentleness  of  disposition,  but  to  the  fact  that  Bembex  is 
not  at  all  handy  with  her  sting,  her  body  being  too  large 
and  clumsy  to  curve  and  give  the  lightning  stab  as  other 
wasps  do.  With  renewed  courage  we  again  approached 
them,  more  cautiously  this  time,  and  soon  learned  that 
if  we  preserved  an  extremely  composed  and  dignified 
demeanor  our  presence  on  the  field  would  be  tolerated. 
119 


WASPS,    SOCIAL   AND    SOLITARY 

Bembex,  like  Philanthus,  and  some  species  of  Sphex, 
lives  in  a  sort  of  semi-social  state,  a  number  of  individ- 
uals occupying  the  same  space  of  ground,  although  each 
one  has  its  separate  nest.  Bembex,  however,  differs 
from  these  genera  and  from  almost  all  of  the  solitary 
wasps  in  her  habit  of  feeding  her  young  from  day  to  day, 
or  rather  from  hour  to  hour,  as  long  as  it  remains  in  the 
larval  state.  This  difference  in  her  maternal  cares  as 
compared  with  those  of  other  species  results  in  a  less 
numerous  progeny.  The  larva,  for  a  period  of  two  weeks, 
demands  constant  attention  from  the  mother,  so  that  a 
second  egg  cannot  be  laid  until  the  first-born  has  gone 
into  its  cocoon,  unless,  indeed,  she  feeds  two  larvae  at 
once,  which  does  not  seem  probable.  The  season  of 
work  is  ten  or  twelve  weeks,  so  that  Wesenberg  is  prob- 
ably correct  in  allowing  only  five  or  six  young  ones  to 
each  mother  for  the  summer. 

In  watching  our  wasps  we  found  that  the  new  nests 
were  usually  made  in  the  outskirts  of  the  colony,  which 
was  thus  continually  extending  its  limits.  Like  many 
other  species,  Bembex  has  great  difficulty  in  deciding 
just  where  to  dig.  Our  Sphex  made  three  beginnings 
before  finally  settling  down.  The  only  Ammophila  that 
we  watched  from  the  beginning  changed  her  place  after 
working  for  ten  minutes.  P.  quinquenotatus  often  tried 


AN   ISLAND    SETTLEMENT 

half  a  dozen  places  before  she  was  satisfied,  and  spinolae 
is  quite  as  difficult  to  please. 

When,  at  last,  the  right  place  is  found,  the  labor  of 
excavation  is  carried  on  vigorously.  The  mandibles  are 
used  for  loosening  the  earth,  and  for  lifting,  but  the 
greater  part  of  the  work  is  done  with  the  first  pair  of  legs, 
the  tarsi  of  which  are  doubled  up  while  the  dirt  is  swept 
out  with  the  brush  of  stiff  spiny  hairs  on  the  second  joint. 
This  attitude  gives  them  a  very  comical  aspect,  making 
them  look  as  if  they  were  sweeping  with  their  elbows. 
They  sometimes  lie  far  over  to  one  side  while  loosening 
the  earth  with  their  mandibles.  While  digging,  the  body 
is  held  high  by  the  straightening  of  the  third  pair  of  legs, 
and  the  dirt  comes  out  behind  in  a  rapid  stream,  flying  to 
a  distance  of  three  or  four  inches.  Before  long  the  wasp 
is  lost  to  sight,  but  every  few  moments  she  comes  back- 
ing out,  pushing  behind  her  the  dirt  that  she  has  dis- 
placed below.  In  about  fifteen  minutes  the  nest  is  ready, 
and  the  wasp  turns  her  attention  to  scattering  all  the 
dirt  that  has  been  thrown  out,  sweeping  the  ground 
clean  so  that  no  sign  of  her  work  remains.  We  have 
often  speculated  as  to  the  meaning  of  the  careful  and 
conscientious  performance  of  this  part  of  her  task.  With 
the  wasps  that  nest  by  themselves  it  is  not  easy  to  see 
what  enemy  they  are  providing  against  in  hiding  the 

121 


WASPS,    SOCIAL   AND    SOLITARY 

entrance  to  the  nest ;  but  the  precaution  seems  still  less 
necessary  —  even  absurd  —  in  the  Bembex  field,  where 
there  is  no  possibility  of  concealing  the  colony,  and 
where  the  nests  are  only  an  inch  or  two  apart,  so  that 
an  enemy  might  burrow  anywhere  with  the  certainty  of 
finding  one.  Moreover,  the  only  enemy  that  we  could 
discover  was  the  parasitic  fly,  which  never  attempts  to 
enter  when  the  hole  is  closed.  However,  unmoved  by 
our  opinion  on  the  subject,  spinolae  spends  five  or  six 
minutes  of  her  precious  time  in  making  the  neighbor- 
hood of  her  home  quite  tidy,  and  then  she  fills  in  the 
mouth  of  the  nest  with  a  little  loose  earth  before  going 
away  to  catch  her  fly. 

Oxybelus,  though  she  is  limited  in  choice  by  her  small 
size,  can  catch  a  fly  in  three  or  four  minutes.  Bembex 
is  strong  enough  to  take  anything  that  she  sees,  and  she 
has  no  preference  for  one  species  above  another,  yet  she 
seldom  finds  one  under  twenty  or  twenty-five  minutes. 
When  she  comes  back  nothing  of  the  fly  is  visible  unless 
it  is  unusually  large,  so  closely  is  it  held  under  her  body 
by  the  second  pair  of  legs.  She  alights,  and  scratches 
away  the  loose  earth  at  the  entrance  of  the  nest  with  her 
first  legs,  and  then,  as  she  creeps  within,  she  passes  the 
fly  along  from  the  second  to  the  third  pair,  so  that  the 
end  of  its  body,  projecting  beyond  the  abdomen  of  the 

122 


AN    ISLAND    SETTLEMENT 

wasp,  is  visible  for  an  instant  before  it  is  carried  inside. 
Sometimes  she  drops  the  fly  behind  her,  and  then,  turn- 
ing around,  pulls  it  in  with  her  mandibles.  In  other 
cases,  where  a  longer  portion  of  the  tunnel  has  been 
filled  with  earth,  the  fly  is  left  lying  on  the  ground  while 
the  wasp  clears  the  way.  This  offers  a  favorable  oppor- 
tunity to  parasites,  especially  as  the  fly  is  not  placed  with 
regard  to  its  safety,  but  is  dropped  anywhere.  The  dirt 
that  is  kicked  out  sometimes  covers  it  so  that  when  the 
way  is  clear  the  careless  proprietor  must  search  it  out  and 
clean  it  off  before  she  can  store  it  away.  In  one  instance, 
in  which  we  had  been  opening  a  nest  close  by,  the  tunnel 
was  entirely  blocked  by  the  loose  earth  which  we  had 
disturbed,  and  the  wasp  worked  for  ten  minutes  before 
she  cleared  a  way  to  her  nest.  During  part  of  this  time 
she  held  the  fly,  but  when  she  realized  that  it  was  going 
to  be  a  long  piece  of  work  she  laid  it  down  near  by.  As 
the  wasp  enters  she  sometimes  leaves  the  hole  open  be- 
hind her,  but  oftener  fills  it  by  pushing  up  earth  from 
below.  When  she  comes  out  again  she  throws  in  a  little 
dirt,  and  then  begins  to  circle  about  the  place.  She 
seems  not  quite  easy  about  the  nest,  however,  returning 
three  or  four  times  to  scratch  earth  over  the  entrance, 
before  finally  taking  her  departure. 
We  opened  a  good  many  nests  in  the  course  of  the 
123 


WASPS,    SOCIAL   AND    SOLITARY 

summer,  and  found  them  all  very  much  alike,  much 
more  so  than  is  the  case  with  other  species.  The  en- 
trance tunnel  runs  in  obliquely  for  from  three  to  five 
inches  below  the  surface  of  the  ground,  and  ends  in  a 
pocket. 

We  grow  accustomed  to  marvels,  and  from  our  famil- 
iarity with  other  wasps  we  take  as  a  matter  of  course  the 
unerring  accuracy  with  which  Bembex  swoops  down 
upon  the  exact  spot  at  which  the  entrance  to  her  nest  is 
hidden.  And  yet  how  strange  a  power  it  is !  There  is  not 
the  least  sign  to  help  her  —  not  a  stone,  not  a  blade  of 
grass  is  to  be  seen  on  the  field.  Our  method  of  marking 
a  nest  which  we  wished  to  find  again  was  to  place  tiny 
pebbles  at  exactly  equal  distances  from  it,  one  on  either 
side,  so  that  the  middle  point  of  the  straight  line  between 
them  gave  us  the  desired  spot;  and  the  wasp  doubtless 
uses  the  same  method,  only  her  landmarks  are  some- 
times so  infinitesimal  that  we  do  not  recognize  them. 

Bouvier  finds  that  when  he  cuts  away  the  plants 
around  the  nest  of  B.  labiatus,  clearing  a  space  of 
twenty-eight  or  thirty  inches  square,  the  wasp  is  much 
confused,  flying  about  for  a  long  time  before  she  is  able 
to  find  her  home.  He  once  placed  a  flat  stone  over  the 
entrance.  The  wasp  alighted  upon  it,  and  after  scratch- 
ing vainly  for  a  while  made  her  way  in.  The  stone  was 
124 


AN   ISLAND    SETTLEMENT 

left  in  this  position  for  two  days,  during  which  time 
Bembex  learned  to  regard  it  as  a  landmark,  for  upon 
its  being  removed  to  a  distance  of  eight  inches  she  still 


NEST   OF    BEMBBX 

followed  it  upon  returning  with  her  fly,  and  insisted 
upon  finding  her  nest  near  it. 

An  observation  of  Marchand  points  to  the  same  con- 
clusion. He  says :  — 

On  July  seventeenth,  1900,  during  a  short  sojourn  at 
Pouliguen,  on  returning  from  a  hunt  after  Diptera  and  Hy- 
menoptera  in  the  cliffs  of  Caudan,  about  eleven  in  the 
morning,  in  tropical  heat,  I  paused  to  take  breath  near 
the  old  mill  of  Caudan  and  looked  about  for  a  little  shade 

125 


WASPS,    SOCIAL   AND    SOLITARY 

before  continuing  my  walk  to  Pen-Chateau.  I  had  seated 
myself  on  the  stones  of  a  slope  shaded  from  the  sun  and 
was  wiping  the  perspiration  from  my  forehead,  when  I 
saw  a  large  wasp  arrive  directly  before  me.  I  instinctively 
followed  it  with  my  eyes ;  it  paused  some  yards  from  the 
mill  on  the  side  of  the  cliff,  and  began  to  open  a  nest 
which  was  placed  scarcely  twenty  inches  from  the  foot  of 
a  swallow-wort,  a  rather  common  plant  in  the  neighbor- 
hood of  the  ruin.  She  was  Bembex  rostrata  at  work  at 
provisioning  her  nest. 

Moved  by  curiosity,  instead  of  going  on  to  breakfast,  I 
awaited  the  exit  from  the  nest,  which  took  place  in  about 
five  minutes.  Bembex  scratched  the  sand  and  took  flight 
from  the  side  of  the  cliff.  How  long  would  she  be  away  ? 
I  looked  at  my  watch  and  arose. 

Ought  I  to  go  or  to  wait  a  little  while  ?  I  took  the  latter 
decision.  Out  of  malice,  and  without  any  idea  of  trying  a 
control  experiment  to  the  admirable  observations  which 
science  owes  to  the  naturalist  of  Serignan,  of  whom  I  was 
not  thinking  at  all,  I  cut  close  to  the  sand  the  stalk  of  the 
swallow-wort  and  planted  it  a  little  nearer  the  mill,  moving 
it  about  two  feet,  and  being  careful  to  put  in  place  of  the 
plant  a  little  fragment  of  a  bottle  which  I  found  in  the  mill. 
I  seated  myself  in  the  shade  and  waited.  Twenty  minutes 
later  the  wasp  dropped  straight  on  to  the  place  where  I  had 
cut  the  plant,  that  is  to  say,  it  deviated  from  its  nest  by  a 
distance  about  equal  to  the  displacement  to  which  I  had 
subjected  the  swallow-wort.  It  walked  right  and  left,  agi- 
tating its  antennae,  appearing  confused  as  to  the  locality. 
126 


AN   ISLAND    SETTLEMENT 

I  followed  these  goings  and  comings  for  two  or  three 
minutes.  Several  times  it  flew  away  and  then  returned, 
always  searching  about.  Pitying  it  and  desiring,  since  I 
was  now  relieved  of  the  fatigue  which  the  heat  had  caused 
me,  to  go  back  to  breakfast,  I  took  my  net  and  drawing 
near,  made  as  if  to  catch  it,  swinging  the  pocket  rapidly 
about.  It  veered  away  with  a  quick  jerk  of  the  wings.  I 
then  took  up  the  swallow-wort,  lifting  the  fragment  which 
marked  its  original  place,  and  replanted  it  in  the  sand. 

I  again  looked  at  my  watch  to  see  whether  I  could  con- 
secrate yet  a  few  more  minutes  to  curiosity  without  mak- 
ing my  kind  host,  my  friend  Dr.  Mce  Rivron,  and  his  wife, 
who  honored  me  with  the  charming  hospitality  of  Kursac, 
wait  too  long.  It  was  only  half  past  eleven ;  we  usually 
did  not  breakfast  until  about  noon;  it  would  take  only  a 
quarter  of  an  hour  to  traverse  the  distance  from  the  mill 
of  Caudan  to  the  house.  I  could  then,  without  fear  of  be- 
ing chided.  dispose  of  fifteen  minutes.  This  lapse  of  time 
would  perhaps  suffice  to  show  me  whether  my  bestiole  would 
this  time  find  the  way  to  her  nest  without  hesitation. 

I  waited  a  little ;  five  minutes  had  not  passed  when  my 
Bembex,  coming  like  an  arrow,  alighted  on  the  sand  near 
the  plant,  still  holding  the  prey  which  I  had  noticed  when 
she  departed  at  my  chasing  her,  after  her  vain  attempts  to 
find  the  entrance  to  her  nest ;  but  this  time  she  did  not 
hunt  long.  She  felt  about  a  little  to  right  and  left,  but 
soon  turned  directly  toward  the  entrance  to  the  tunnel, 
distant  scarcely  two  inches  from  the  place  where  she  had 
settled.  My  Bembex  had  a  memory. 
127 


WASPS,    SOCIAL   AND    SOLITARY 

A  curious  thing  about  these  wasps,  and  one  which 
shows  how  much  common  feeling  they  have,  is  that  they 
work  in  waves,  all  starting  off  on  their  hunting  expedi- 
tions within  a  few  minutes  of  each  other,  and  returning 
together  after  the  chase.  At  one  time  all  the  residents 
seem  to  be  present,  digging  their  nests,  carrying  in  their 
booty,  dashing  at  each  other,  and  chasing  the  parasites 
with  a  tremendous  amount  of  humming  and  swooping 
about.  Then  suddenly  they  are  all  gone.  Nothing  re- 
mains but  multitudes  of  flies,  which  keep  up  a  giddy 
dance  over  the  field,  and  for  ten  or  fifteen  minutes  the 
place  seems  deserted.  Then  the  wasps  begin  to  return, 
several  coming  at  a  time,  and  as  if  by  magic  the  whole 
scene  awakens  to  life.  More  than  half  of  the  wasps  bring 
nothing  home  with  them,  and  these  fall  to  robbing  their 
more  fortunate  companions.  Those  that  are  carrying 
flies  must  pause  a  moment,  burdened  as  they  are,  to 
scratch  away  the  earth  at  the  entrance  to  the  nest.  When 
unmolested  they  go  in  very  quickly,  but  it  is  just  at  this 
point  that  the  marauders  fall  upon  them,  displaying  an 
amount  of  persistence  and  energy  in  their  attacks  that, 
were  it  properly  directed,  might  easily  enable  them  to 
secure  flies  for  themselves. 

We  once  saw  a  wasp  that  had  been  fortunate  enough, 
or  perhaps  unfortunate  enough,  to  catch  an  immense 
128 


AN   ISLAND    SETTLEMENT 

fly,  the  wings  of  which  stood  out  on  both  sides  very  con- 
spicuously. This  made  her  an  especial  mark  for  her 
unprincipled  relatives.  Half  a  dozen  of  them  chased  her 
about,  like  chickens  pursuing  one  of  their  number  that 
has  found  a  worm.  She  circled  and  settled,  and  circled 
and  swooped  around  for  five  or  six  minutes,  continually 
pursued  and  attacked  by  the  robbers,  and  quite  unable 
to  get  into  her  nest.  At  last,  curious  to  see  what  she  was 
carrying,  we  made  her  drop  her  load,  and  secured  it  for 
ourselves.  We  found  it  to  be  a  horse  fly,  quite  dead,  but 
showing  no  marks  of  violence.  It  was  not  wasted,  for 
we  afterward  fed  it  to  one  of  our  wasp  nurslings  at  home. 
At  another  time  we  saw  one  wasp  attack  another  that 
was  bringing  in  a  fly.  In  the  struggle  that  ensued  the 
owner  lost  her  booty,  as  the  two  rolled  over  and  over  on 
the  ground,  and  as  they  parted  it  was  seized  by  the  thief. 
They  clinched  again,  and  rolled  on  the  ground  as  before, 
and  this  time  the  fly  was  recovered  by  the  rightful  owner. 
At  this  point,  thinking  that  perhaps  one  of  the  wasps 
was  a  male,  and  that  this  might  be  their  style  of  court- 
ship, we  seized  both  of  them;  whereupon  the  fly  was 
dropped,  and  the  two  wasps  turned  their  attention  to 
attacking  us.  Both  proved  to  be  females.  Not  only  do 
the  Bembecids  fight  in  this  way  for  the  possession  of 
their  prey  —  they  quarrel  even  without  apparent  cause. 
129 


WASPS,    SOCIAL   AND    SOLITARY 

We  have  seen  two  females  digging  their  nests  at  a  little 
distance  apart,  one  of  which  was  repeatedly  attacked  by 
the  other,  although  she  did  nothing  to  provoke  the  ag- 
gressor. They  are  certainly  very  unneighborly,  and  have 
no  idea  of  living  in  harmony.  When  flying  in  a  threaten- 
ing manner,  either  at  us  or  at  each  other,  they  have  a 
way  of  wagging  their  abdomens  violently  from  side  to 
side  in  a  way  well  calculated  to  inspire  terror. 

In  warm  sunny  weather  spinolae  works  industriously 
through  the  middle  of  the  day,  and  seems  determined  to 
provide  abundantly,  not  only  for  her  own  offspring,  but 
for  any  unbidden  guests  that  it  may  be  her  fate  to  care 
for.  She  never  works  more  than  four  or  five  hours  a  day, 
however,  and  in  unfavorable  weather  she  does  not  work 
at  all.  On  going  over  to  the  island  one  cloudy  morning 
to  spend  some  hours  in  watching  the  Bembex  activities, 
we  found  the  spot  quiet  and  lifeless.  No  one  seeing  it  for 
the  first  time  would  have  dreamed  of  the  multitudes  of 
living  creatures  beneath  his  feet.  The  nests  seemed  to 
be  all  closed,  but  on  peering  curiously  about  we  found 
one  on  sloping  ground,  in  the  suburbs  of  the  colony,  of 
which  the  door  was  open.  Just  within  was  the  proprietor 
gazing  out  on  the  landscape,  as  she  is  shown  in  the  illus- 
tration. She  seemed  to  be  leaning  on  her  elbows,  and 
her  face,  enlivened  by  two  great  goggle  eyes,  had  an 
130 


AN   ISLAND    SETTLEMENT 

irresistibly  comical  aspect.  With  the  exception  of  the 
omnipresent  flies,  this  wasp  was  the  only  sign  of  life 
about  the  place.  Even  in  good  weather,  and  in  working 


BEMBEX   SPINDLY    LOOKING   OUT   OF   NEST 

hours,  the  wasps  sometimes  rest,  for  we  have  seen  them 
go  in  empty-handed,  closing  the  door  behind  them,  to 
remain  for  half  an  hour  at  a  time. 

There  is  one  thought  that  must  strike  even  a  casual 
observer  at  the  sight  of  the  hordes  of  parasites  that 
hover  over  a  Bembex  colony:  — 


WASPS,    SOCIAL    AND    SOLITARY 

"  The  buzzing  flies,  a  persevering  train, 
Incessant  swarm,  and  chased  return  again." 

Why  do  not  these  wasps,  fly- catchers  as  they  are  by  pro- 
fession, kill  the  worthless  wretches  that  infest  their 
homes,  thriving  abundantly  on  the  fruits  of  their  labor, 
a  continual  menace  to  the  life  and  safety  of  their  off- 
spring ?  To  the  uninitiated  it  would  seem  that  these  flies 
might  serve  as  food  for  the  wasp  larvae  quite  as  well  as  any 
of  the  dozen  species  that  they  actually  take;  but  even  if 
the  wasp-mother  believes  that  they  possess  indigestible 
qualities,  it  would  be  much  less  trouble  to  kill  them  and 
throw  them  away  than  to  be  perpetually  chasing  them 
to  a  little  distance  only  to  see  them  return  as  soon  as 
she  gives  her  attention  to  anything  else.  Whatever  the 
reason  for  it  may  be,  the  relation  between  the  wasps  and 
the  flies  is  certainly  most  curious  and  puzzling.  Fabre's 
explanation  is  that  since  this  miserable  little  fly  has  its 
own  part  to  play  in  nature,  Bembex  must  respect  it, 
thus  preserving  harmony  in  the  world  of  living  things. 
The  idea  is  perfectly  in  accord  with  his  own  theories, 
but  we  find  ourselves  quite  unable  to  accept  it. 

There  can  be  no  doubt  that  the  parasites  are  a  grave 

danger  to  Bembex.  She  suffers  from  them  far  more  than 

any  other  wasp  that  we  are  familiar  with,  her  mode  of 

feeding  the  young  rendering  her  peculiarly  susceptible 

132 


AN   ISLAND    SETTLEMENT 

to  their  attacks.  Of  the  ten  or  twelve  nests  that  we 
opened  only  one  was  free  from  them,  the  others  con- 
taining from  two  to  five  lively  maggots  nearly  as  large 
as  the  wasp  larvae,  which  were  sharing  the  food  brought 
in  by  the  mother.  Fabre,  who  has  studied  the  question 
thoroughly,  has  found  as  many  as  ten  parasitic  larvae  in 
one  nest.  He  has  also  noticed  that  where  the  parasites 
are  most  numerous  the  wasp-larva  is  proportionately 
small  and  emaciated,  reaching  only  one  half  or  one  third 
of  its  normal  size.  When  it  attempts  to  spin  its  cocoon 
it  has  not  strength  enough  to  do  so,  and  thus  perishes 
miserably  among  the  pupae  of  the  interlopers,  which  have 
the  advantage  of  developing  more  rapidly.  He  has  proved, 
by  experiments  upon  nests  transported  to  his  study,  that 
although  the  invaders  preserve  friendly  relations  with 
the  rightful  owner  of  the  nest  so  long  as  food  is  abun- 
dant, they  nevertheless,  at  the  first  suggestion  of  scarcity, 
fall  upon  the  wasp  larva  and  ruthlessly  devour  it.  This 
"  black  action"  he  has  seen  with  his  own  eyes.  In  view 
of  this  base  ingratitude,  we  are  more  than  ever  impressed 
with  the  troubles  of  the  poor  Bembex  mother,  as  she 
tries  to  feed  a  dozen  mouths  where  she  has  bargained  for 
only  one. 

We  several  times  saw  a  fly  follow  a  wasp  into  her  nest, 
remaining  within  for  half  a  minute,  and  it  is  probable 
133 


WASPS,    SOCIAL   AND    SOLITARY 

that  they  go  in  to  lay  their  eggs.  According  to  Fabre,  it 
is  the  habit  of  the  flies  that  are  parasitic  upon  the  half- 
dozen  species  of  Bembex  that  he  has  studied  to  seize  the 
moment  at  which  the  fly  projects  from  under  the  abdo- 
men of  the  wasp  as  she  enters  the  nest ;  and  he  has  even 
known  them  to  lay  two  or  three  eggs  on  one  fly  in  the 
instant  of  time  that  its  body  was  exposed. 

Fabre  took  a  partly  grown  Bembex  larva  from  the 
nest,  where  it  was  surrounded  by  the  remains  of  twenty 
flies.  He  fed  it  generously,  and  it  ate  sixty-two  more, 
making  a  total  of  eighty-two  in  the  eight  days  that 
passed  before  the  spinning  of  the  cocoon.  Our  experi- 
ments in  this  line  gave  similar  results.  We  took  charge 
of  a  partly  grown  larva  on  the  afternoon  of  August  tenth, 
and  between  that  date  and  August  fifteenth,  when  it 
spun  its  cocoon,  it  ate  forty-two  house  flies  besides  a  big 
Tabanus. 

Fabre  thinks  that  under  natural  conditions  the  mother 
does  not  give  the  larva  all  it  can  eat  at  one  time,  but  pro- 
vides it  with  what  she  considers  a  reasonable  amount  of 
food,  and  keeps  anything  that  she  catches  beyond  this 
out  of  its  reach.  He  draws  his  conclusion  from  the  fact 
that  he  has  found  several  flies  in  the  tunnel  leading  to  the 
nest,  while  the  larva  had  as  many  more  close  to  it.  It 
would  certainly  be  convenient  for  Bembex  to  have  a 


AN    ISLAND    SETTLEMENT 

reserve  of  this  kind  in  case  of  rainy  weather,  but  the 
forethought  implied  in  such  an  action  seems  to  require 
a  higher  degree  of  intelligence  than  can  be  claimed  for 
her. 

In  one  nest  we  found  a  single  fly  with  a  long  cylindri- 
cal egg  attached  to  the  left  side  of  the  thorax  just  at  the 
origin  of  the  third  leg.  In  another,  which  we  had  seen 
made  and  provisioned,  we  found,  six  days  later,  a  larva 
which  we  judged  to  be  four  days  old.  Assuming  that  the 
egg  was  laid  on  the  first  day,  it  must  have  taken  it  about 
two  days  to  hatch.  Other  nests  gave  us  larvae  in  all 
stages  of  development,  surrounded  by  the  remains  of 
Diptera,  among  which  Syrphus,  Tabanus,  and  Musca 
were  represented. 

In  regard  to  the  condition  of  the  flies  captured  by 
Bembex,  we  have  never  seen  the  crushing  of  the  thorax, 
which  is  noted  by  both  Wesenberg  and  Fabre.  Indeed, 
the  flies  that  we  found  were  not  always  dead,  since  in 
two  instances  they  responded  readily  to  stimulation. 
Similar  results  have  been  obtained  by  Mr.  S.  W.  Dun- 
ning of  Hartford,  Connecticut. 

Twice  we  have  seen  our  spinolae,  as  she  was  bringing 
home  her  prey,  alight  near  the  nest  and  sting  it  as  it  was 
held  with  the  second  pair  of  legs.  We  could  see  the  pro- 
cess distinctly,  since  she  is  slow  and  clumsy,  and,  in  one 
135 


WASPS,    SOCIAL   AND    SOLITARY 

instance,  had  difficulty  in  reaching  the  fly,  falling  over 
to  one  side  in  an  awkward  manner.  It  is  probable,  then, 
that  this  is  a  habit  with  the  wasp,  but  that  the  sting  is 
usually  given  at  the  place  of  capture. 

We  opened  a  number  of  Bembex  nests,  but  succeeded 
in  raising  only  one  larva,  which  we  took  when  it  was  half 
grown.  This  one,  during  the  five  days  that  passed  before 
it  spun  the  cocoon,  ate  forty-three  flies. 

Mr.  Bates  has  some  notes  on  Monedula  signata,  which 
takes  nothing  but  flies,  and  even  confines  itself  to  a  single 
species,  although  it  must  sometimes  go  half  a  mile  away 


to  find  it.  This  reminds  us  of  Pompilus  quinquenotatus, 
which  never  takes  anything  but  Epeira  strix. 

A  considerable  contribution  to  our  knowledge  of  the 
genus  Bembex  has  been  made  in  the  paper  by  Wesen- 
136 


A    CORNER    OF    THE    BEMBEX    COLONY 


AN  ISLAND   SETTLEMENT 

berg  (written  in  Danish)  which  has  already  been  referred 
to.  This  paper  deals  with  Bembex  rostrata.  It  was  trans- 
lated for  Mr.  Ashmead  by  Mr.  Martin  Linell. 

It  seems  that  rostrata  makes  its  nest  in  solid  sand, 
covering  it  up  with  loose  sand,  and  usually,  also,  with  a 
little  flat  stone,  to  prevent  parasites  from  entering.  The 
cell  measures  one  cubic  inch,  the  entrance  tunnel  being 
one  and  one  half  centimeters  long,  and  arcuate.  A  cell 
contains  four  or  five  fresh  flies  (Lucilia,  Eristalis,  etc.), 
and  torn-off  wings,  sucked-out  thoraces,  and  in  the  mid- 
dle of  these,  a  big  flat  larva. 

When  the  larva  is  hatched  the  mother  brings  more 
and  more  flies,  the  flies  being  larger  and.  larger  as  it 
grows.  This  adjustment  of  the  size  of  the  fly  to  the 
growth  of  the  larva  has  also  been  noted  by  Fabre. 

Wesenberg  says  that  fifty  Bembecids  will  nest  on  a 
spot  as  big  as  a  room  during  a  period  of  three  months. 
The  time  required  for  the  development  of  the  larva  is 
two  weeks,  this  giving  five  or  six  young  ones  for  the 
season.  He  queries,  "  Does  each  female  have  more  than 
one  nest?  and  if  so,  how  can  she  remember  them?" 
To  determine  this  point  we  marked  six  wasps  by  touch- 
ing them  with  differently  colored  paints,  putting  near 
their  nests  pebbles  painted  to  correspond  with  the 
owners,  and  then  watched  them  closely  for  three  hours. 
139 


WASPS,    SOCIAL   AND    SOLITARY 

During  this  time  the  red  wasp  returned  regularly  to  the 
red  nest,  the  blue  to  the  blue,  and  so  on.  They  were 
watched  for  an  hour  and  a  half  on  the  following  day 
with  the  same  result,  so  that  it  seems  quite  certain  that 
spinolae  has  only  one  nest  at  a  time.  To  feed  two  larvae 
at  once,  with  interlopers  thrown  in,  would  be  a  heavier 
task  than  the  most  determined  industry  could  accom- 
plish. 


Chapter  VII 

THE    BURROWERS 

DUFOUR,  in  describing  the  fearful  ravages  of  Cer- 
ceris  ornata  among  the  bees,  says  that  the  wasps 
of  this  genus  are  among  other  insects  what  eagles  and 
hawks  are  among  birds.  While  this  characterization 
does  not  seem  to  fit  the  American  species,  it  is  certainly 
true  that  the  genus  stands  out  as  one  of  those  in  which 
the  distinctive  peculiarities  are  strongly  marked.  They 
might  be  considered  the  aristocrats  in  the  world  of  wasps, 
their  habits  of  reposeful  meditation  and  their  calm,  un- 
hurried ways  being  far  removed  from  the  nervous  man- 
ners of  the  Pompilidae  or  the  noisy,  tumultuous  life  of 
Bembex.  Their  intelligence  is  shown  by  their  reluctance 
to  betray  their  nests,  and  by  their  uneasiness  at  any 
slight  change  in  the  objects  that  surround  them.  It  is 
not  necessary  to  attempt  to  catch  them  or  to  make 
threatening  gestures,  in  order  to  arouse  their  sense  of 
danger.  If  you  are  sitting  quietly  by  a  nest  when  the 
wasp  opens  her  door  in  the  morning  she  will  notice  you 
at  once,  and  will  probably  drop  out  of  sight  as  though 
141 


WASPS,    SOCIAL   AND    SOLITARY 


she  resented  your  intrusion  into  her  privacy.  After  a 
little  she  will  come  up  again  and  will  learn  to  tolerate 
you,  but  at  the  least  movement  on  your  part,  almost  at 
the  winking  of  an  eyelid,  she  will  disappear. 

Our  four  representatives  of  this  genus  all  prey  upon 
beetles  that  are  injurious  to 
vegetation,  and  therefore  de- 
serve the  gratitude  of  agri- 
culturists. Nigrescens,  with 
her  pale  grayish  bands,  is  a 
very  trying  wasp  to  deal  with. 
We  had  seen  her  flying  about 
in  the  garden  for  weeks  be- 
fore we  succeeded  in  track- 
ing her  home,  and  when  we 
did  succeed  she  was  so  late 
about  getting  up  in  the  morn- 
ing, stayed  away  from  home 
so  many  hours  at  a  time,  and 
went  to  bed  so  early  in  the 
afternoon,  that  we  were  not 
well  repaid  for  watching  her 
nest  all  day.  Fumipennis, 
large  and  handsome,  with  a  broad  yellow  band  at  the 
front  of  the  abdomen,  is  another  wasp  that  has  no 
142 


NEST    OF    CERCERIS    NIGRESCENS 


THE    BURROWERS 

regard  for  the  convenience  of  the  people  who  are  watch- 
ing her.  You  may  sit  by  her  big  open  hole  for  hours 
without  seeing  her,  and  when  she  comes  she  drops  in 
so  suddenly  that,  unless  you  are  very  much  on  your 
guard,  you  are  not  sure  even  then  what  she  is.  Clypeata 
and  deserta  are  better  subjects  for  study. 

The  nests  of  our  species  are  all  deep,  tortuous,  and 
very  difficult  to  excavate.  We  have  never  succeeded  in 
finding  their  pockets; 
and  yet,  for  various 
reasons,  we  feel  per- 
fectly certain  that  all 
of  them  are  like  C. 
ornata  in  provisioning, 
successively,  a  number 
of  cells  which  lead  out 

CERCERIS   CLYPEATA 

of   the    main   gallery. 

When  one  of  these  cells  is  filled  with  food,  and  the  egg 
deposited,  it  is  probably  closed  up,  and  thus  separated 
from  the  runway.  From  our  experience  late  in  the 
season  with  the  nests  of  another  wasp,  we  are  inclined 
to  think  that  we  made  a  mistake  in  looking  for  pock- 
ets at  the  lower  end  of  the  tunnel.  Had  we  searched 
higher  up,  at  the  point  of  the  curve,  we  might  have 
found  them,  the  lower  part  of  the  gallery  probably  being 


WASPS,    SOCIAL   AND    SOLITARY 

designed  merely  for  a  dwelling-place  for  the  mother  of 
the  family. 

But  although  we  did  not  get  distinct  pockets,  there 
was,  in  at  least  one  nest,  a  supply  of  food  that  would 
have  far  exceeded  the  wants  of  a  single  larva.  We 
did  not  succeed  in  finding  eggs  on  different  groups  of 
beetles;  but  from  a  nest  into  which  the  wasp  was  still 
carrying  food  we  took  a  half-grown  larva  which  was 
identified  as  being  hers.  The  fact,  too,  that  a  wasp  occu- 
pies a  nest  for  so  long  a  time  as  ten  days  or  two  weeks 
points  to  the  conclusion  that  she  uses  it  for  a  number  of 
eggs  which  are  laid  at  intervals. 

Cerceris  digs  her  nest,  deep  as  it  is,  all  at  once.  In 
this  she  is  a  contrast  to  her  near  relatives  of  the  genus 
Philanthus,  who  busy  themselves  for  an  hour  or  so  every 
morning  with  fresh  excavations. 

On  the  eighth  of  July  the  weather  was  so  warm  and 
bright  that  we  went  down  to  the  garden  at  half  past 
eight  o'clock,  knowing  that  it  was  rather  early,  but 
hoping  that  the  hot  sunshine  would  tempt  the  wasps 
to  industry.  We  had  walked  up  and  down  several  times, 
when  suddenly,  right  in  the  pathway,  a  nest  appeared. 
A  great  quantity  of  loose  earth  had  been  taken  out  and 
heaped  up,  probably  on  the  preceding  day,  and  in  the 
midst  of  this  a  little  hole  had  been  opened  since  we 
144 


THE    BURROWERS 

passed  before.  The  place  looked  so  promising  that  we 
sat  down  to  watch  it,  and  a  few  minutes  later  we  were 
rewarded  by  a  glimpse  of  some  antennae  down  the  gal- 
lery, and  then  a  little  face  with  yellow  markings  appeared 
but  quickly  vanished.  Now  followed  a  very  coquettish 
performance.  The  wasp  came  slowly  creeping  up  again 
and  again,  only  to  drop  out  of  sight  as  soon  as  she  had 
reached  the  opening.  After  a  time  she  grew  bolder,  and 
sat  in  her  doorway,  twitching  her  head  this  way  and 
that  in  a  very  expressive  manner,  as  though  she  were 
planning  the  work  of  the  day;  but  it  was  plain  that 
although  she  was  up  early,  business  cares  were  not 
weighing  heavily  upon  her  mind,  for  forty  minutes 
passed  before  she  came  out  of  the  nest,  and  after  making 
three  or  four  circles  about  the  spot,  flew  away. 

How  much  livelier  and  more  interesting  it  would  have 
been  if  we  could  have  followed  her!  We  tried  to  guess 
at  what  she  was  doing,  and  imagined  her  hunting  in- 
dustriously. After  fifteen  or  twenty  minutes  it  seemed 
to  us  that  she  must  have  caught  something,  and  that 
she  was  surely  returning.  Most  probably  she  was  not 
working  at  all,  but  was  breakfasting  leisurely  and  ex- 
changing compliments  with  her  neighbors ;  for  when  she 
did  come  home  after  keeping  us  waiting  for  an  hour 
and  a  half,  she  brought  nothing  with  her,  and  seemed 
145 


WASPS,    SOCIAL   AND    SOLITARY 

quite  unconscious  of  the  fact  that  greater  things  had 
been  expected  of  her. 

We  had  placed  a  stone  upon  a  dead  leaf  near  by,  to 
mark  the  neighborhood  of  the  nest,  thinking  that  even  a 
Cerceris  could  not  object  to  so  simple  an  arrangement 
of  natural  objects;  but  our  wasp  noticed  it  at  once,  and 
evidently  with  much  suspicion  and  disapproval.  She 
began  by  circling  several  times  just  above  it.  Then  she 
alighted  on  it  and  examined  it  carefully,  walking  over 
it,  and  creeping  underneath,  perhaps  to  see  whether  it 
in  any  way  menaced  the  safety  of  her  nest,  perhaps  as 
the  completion  of  a  locality  study  made  the  day  before. 
She  then  rose  on  her  wings,  and  after  a  little  more  cir- 
cling, dropped  suddenly  into  her  hole. 

So  far  we  had  not  been  getting  on  very  rapidly,  but 
from  this  time  things  took  a  turn.  Cerceris  is  never  in  a 
hurry,  and  yet  she  may  be  relied  upon  to  do  a  certain 
amount  of  work  every  day.  The  one  that  we  were  now 
watching  had  probably  come  back  for  a  final  look  at  her 
newly  made  nest  before  beginning  to  provision  it;  for 
she  soon  reappeared,  and  this  time  really  went  to  work, 
since  in  forty  minutes  she  brought  home  a  beetle  which 
she  carried  by  the  snout,  venter  up,  in  her  mandibles, 
supporting  it  with  the  second  pair  of  legs  while  flying. 
She  was  much  annoyed  at  our  presence,  and  circled 
146 


THE    BURROWERS 

about  as  before.  Twice  she  alighted  near  by,  and  walked 
around  for  a  few  minutes,  and  when  she  did  this  all 
her  feet  came  down  to  the  ground,  the  beetle  being 
allowed  to  hang  loosely.  At  last  she  made  the  best  of  a 
bad  matter,  and  went  in.  The  rest  of  the  morning  was 
occupied  with  hunting,  the  capture  of  each  beetle  taking 
about  forty-five  minutes.  Every  time  that  she  came 
home  she  spent  fifteen  or  twenty  minutes  in  the  nest. 

This  species  soon  became  very  common,  and  for  two 
weeks  scarcely  a  morning  passed  without  our  finding  at 
least  one  newly-made  nest.  The  study  of  clypeata,  how- 
ever, consumes  a  great  deal  of  time.  For  example,  we 
found,  one  morning,  two  nests  within  six  inches  of  each 
other.  It  turned  out  afterward  that  these  were  inhabited 
by  two  different  wasps;  but  at  the  moment  we  supposed 
that  one  of  them  had  been  dug  and  deserted  and  then  a 
second  one  made,  and  wishing  to  know  which  one  was 
occupied  we  resolved  to  watch  and  see.  After  waiting 
for  three  hours  we  saw  one  wasp  returning;  but  upon 
noticing  us  she  veered  off  and  began  to  circle  about. 
She  was  heavily  laden,  and  her  burden,  instead  of  being 
supported  by  the  second  pair  of  legs,  as  is  sometimes  the 
case,  hung  down  under  the  thorax  and  abdomen.  After 
a  moment  she  alighted  on  a  plant  near  by,  and  seemed 
to  consider  the  situation,  then  circled  a  little  more,  and 


WASPS,    SOCIAL   AND    SOLITARY 

flew  away,  remaining  out  of  sight  for  fifteen  minutes, 
then  another  return,  more  circlings  and  hesitations.  She 
seemed  to  feel  the  weight  of  the  beetle  now,  and  alighted 
frequently  on  the  ground  and  walked  about;  yet  she 
would  not  go  in,  so  reluctant  was  she  to  betray  her  nest.  ; 
In  this  way  she  kept  us  waiting  for  a  whole  hour, 
although  we  were  not  very  near  to  her,  and  were  as 
still  as  statues.  At  last  we  retreated,  and  stood  as  far 
back  as  we  could  and  still  keep  the  hole  in  view.  She  • 
now  came  closer,  and,  after  hanging  poised  on  her  wings 
for  a  moment,  dropped  into  her  nest. 

We  once  found  a  nest  of  this  species  in  process  of  con- 
struction. A  large  heap  of  fresh  earth  had  been  pushed 
out,  which  entirely  covered  the  spot;  but  at  intervals 
there  were  upheavals  from  below  which  betrayed  the 
presence  of  the  wasp.  When  we  saw  it  first  it  was  half 
past  eight  o'clock,  and  we  judged,  from  what  had  been 
accomplished,  that  she  must  have  been  at  work  at  least 
an  hour.  It  was  half  past  nine  before  the  excavation  was 
complete.  We  had  not  been  certain,  up  to  this  time,  as 
to  what  we  were  watching ;  but  now  we  had  the  pleasure 
of  seeing  her  open  her  doorway  from  below  and  stand 
in  the  entrance  while  she  washed  her  face  with  her  fore 
feet,  like  a  cat.  When  they  rest  at  the  mouth  of  the  hole 
the  first  legs,  which  are  yellow,  are  bowed  in  a  semi- 
148 


THE    BURROWERS 

circle  on  each  side  of  the  yellow  face,  the  distal  joints 
being  bent  up  so  that  the  wasps  seem  to  be  standing  on 
their  elbows.  This  attitude,  which  is  often  seen  in  Bem- 
bex  spinolse,  gives  them  a  delightfully  amusing,  bow- 
legged  appearance.  They  usually  open  their  nests  in  the 
morning  at  about  nine  o'clock,  —  a  little  earlier  or  later 
according  to  the  time  at  which  the  sun  strikes  the  spot. 
Then  they  spend  from  forty  minutes  to  an  hour  in  taking 
a  survey,  the  least  movement  on  the  part  of  a  watcher 
causing  them  to  drop  out  of  sight  as  if  the  earth  had 
given  way  beneath  them.  Sometimes  there  is  a  little 
way-station  an  inch  or  two  within  the  tunnel,  and  the 
wasp  falls  back  only  to  this  point,  and  here  she  may  be 
seen,  if  one  peeps  in  cautiously,  either  quietly  awaiting 
the  retreat  of  the  intruder,  or,  perhaps,  performing  her 
toilet  in  a  leisurely  and  elegant  manner. 

Whenever  she  leaves  her  nest  she  makes  three  or  four 
rapid  circles  around  the  spot  to  freshen  her  memory  of 
the  locality.  The  most  thorough  study  that  we  saw 
made  by  clypeata  was  in  the  case  of  the  wasp  mentioned 
before,  that  was  so  long  in  carrying  her  beetle  in  because 
of  our  being  on  the  ground.  When  she  finally  did  go  in 
she  stayed  only  an  instant  —  just  long  enough  to  de- 
posit her  load  —  and  then  came  out  and  spent  a  long 
time  in  an  investigation  of  all  the  surrounding  objects, 
149 


WASPS,    SOCIAL   AND    SOLITARY 

flying  in  and  out  among  the  plants,  now  high,  now  low, 
and  circling  again  and  again  around  the  spot.  It  looked 
as  though  she  had  been  puzzled  and  disturbed  by  the 
presence  of  unaccustomed  things.  As  soon  as  the  survey 
was  over  she  went  inside  and  closed  the  door,  as  though 
its  object  had  been  not  so  much  to  strengthen  her  mem- 
ory as  to  correct  former  impressions. 

The  work  of  bringing  in  beetles  goes  on  very  irreg- 
ularly, and  as  a  rule  not  more  than  two  or  three  are 
stored  in  the  course  of  a  day.  It  is  not  unusual  for  cly- 
peata  to  spend  three  or  four  hours  away  from  home  and 
then  come  back  without  anything  ;  and  often,  even  in 
the  middle  of  the  day,  she  passes  an  hour  or  two  in  the 
seclusion  of  her  nest.  We  had  several  nests  under  obser- 
vation for  a  week  at  a  time  without  ever  once  seeing  the 
owners,  although  they  were  evidently  occupied,  since 
they  were  sometimes  open  and  sometimes  closed.  The 
outer  entrance  is  always  left  open  when  the  wasp  goes 
away,  although  possibly  access  to  the  pockets  may  be 
barred  below;  but  when  she  enters  she  closes  the  door 
unless  she  means  to  come  out  again  at  once.  The  closing 
is  sometimes  effected  by  pushing  the  earth  up  backwards, 
with  the  end  of  the  abdomen;  but  the  hole  is  rather  too 
large  for  this  method,  and  more  frequently  the  wasp  . 
comes  up  head  first,  carrying  a  load  of  earth  in  her  front 
150 


THE    BURROWERS 

legs.  This  is  placed  just  within  and  to  one  side  of  the 
entrance,  and  then  more  armfuls  are  brought  up,  until, 
after  two  or  three  trips,  the  opening  is  entirely  filled. 

We  once  captured  the  wasp  in  a  bottle,  as  she  re- 
turned, loaded,  to  the  nest.  She  dropped  the  beetle, 
but  soon  picked  it  up  again  and  stung  it  vigorously,  with 
intention,  as  the  French  say,  first  under  the  neck,  and 
then  further  back,  behind  the  first  pair  of  legs.  After 
this  it  was  dropped  while  the  wasp  fluttered  about  for  a 
few  minutes,  but  it  was  then  picked  up  again,  and  stung 
as  before.  We  both  saw  this  operation  repeated  in 
exactly  the  same  way,  four  different  times,  with  intervals 
of  five  or  six  minutes  between. 

In  a  nest  which  we  excavated  after  watching  it  for 
nine  days,  we  found  nothing  until  we  had  gone  six  inches 
down,  and  at  this  point  the  tunnel  was  lost;  but  mixed 
with  the  crumbly  earth  that  we  took  out  of  the  hole,  we 
found  eight  beetles  and  a  half-grown  larva  of  clypeata. 
The  destruction  of  this  nest  was  accomplished  one 
morning,  and  when  we  came  back  to  the  spot  twenty- 
four  hours  later  we  found  that  a  new  one  had  been  made 
close  by,  doubtless  by  the  same  individual.  We  had  ex- 
pected to  find  her  bringing  beetles  and  dropping  them 
foolishly  on  the  ground  like  Paul  Marchal's  Cerceris 
ornata,  and  were  gratified  that  she  showed  an  advance 


WASPS,    SOCIAL   AND    SOLITARY 

in  intelligence  over  that  species,  although  to  be  sure  she 
would  have  been  still  wiser  had  she  chosen  an  entirely 
new  neighborhood.  Another  individual  was  so  much 
disturbed  by  our  scrutiny  that  she  dropped  her  beetle 
at  the  entrance  to  her  nest.  She  did  not  pick  it  up  again 
and  utilize  it,  although  it  lay  for  three  days  in  the  dust  at 
the  threshold. 

As  to  the  condition  of  the  beetles  stored  by  clypeata: 
in  the  first  nest  that  we  opened  we  found  eight,  seven  of 
which  were  dead,  while  the  eighth,  which  we  had  just 
seen  stung  several  times,  was  alive,  but  died  on  the  fol- 
lowing day.  The  second  nest  gave  us  five  beetles,  all  of 
them  dead  and  dry.  In  the  other  nests  that  we  opened 
we  found  nothing,  though  we  knew  that  the  beetles  were 
there  had  we  only  been  skillful  enough  to  discover  them. 

Of  Cerceris  deserta,  which  closely  resembles  clypeata, 
but  appears  later  in  the  season,  we  had  only  a  single  ex- 
ample. We  chanced  to  see  her  dropping  into  a  crevice 
among  some  lumps  of  earth,  and  at  first  could  scarcely 
believe  that  this  was  the  dwelling-place  of  a  wasp,  as 
there  was  nothing  whatever  about  it  to  indicate  a  nest; 
and  even  after  we  had  removed  the  rough  pieces  of  earth 
above,  we  could  see  nothing  of  the  loose  material  that 
must  have  been  carried  out. 

She  was  much  like  clypeata  in  her  manners,  with  the 


THE    BURROWERS 

same  habit  of  surveying  the  world  from  her  doorway, 
and  manifesting  the  same  annoyance  at  our  presence 
when  she  was  returning  to  the  nest;  but  she  carried  in 
more  beetles  in  the  course  of  the  day  and  worked  much 


CERCERIS  DESERTA:   LOCALITY  STUDY  BEFORE 
LEAVING  NEST 

more  rapidly.  Between  nine  and  eleven  o'clock  one 
morning  she  brought  in  five  loads,  and  some  of  the 
journeys  occupied  only  ten  minutes. 

The  first  time  that  she  found  us  sitting  by  her  nest  she 

circled  about  for  nearly  an  hour,  seeming  unable  to 

make  up  her  mind  to  enter.    At  length  we  withdrew  a 

little  way,  but  still  her  suspicions  were  not  entirely 

153 


WASPS,    SOCIAL   AND    SOLITARY 

allayed;  and  after  a  further  study  of  the  situation  she 
dropped,  not  into  her  own  nest,  but  into  a  large  cricket 
hole  near  by.  Taken  aback  by  this  manoeuvre,  and 
thinking  that  perhaps  we  had  a  second  individual  to 
deal  with,  we  stealthily  approached,  and  peering  in, 
could  see  the  cricket  inside,  the  wasp  having  slipped 
beyond.  It  did  not  seem  possible  that  the  little  creature 
could  be  endeavoring  to  deceive  us,  and  yet  what  other 
explanation  could  be  offered  for  her  conduct  ?  We  again 
took  up  our  distant  position,  and  after  ten  minutes  more 
had  the  satisfaction  of  seeing  the  wasp  slip  out  of  the 
false  nest  and  drop  instantly  into  the  true  one.  After  a 
little  she  became  quite  accustomed  to  us,  and  entered 
her  nest  without  the  least  delay. 

The  prey  of  deserta  is  held  in  the  mandibles,  and 
while  we  were  watching  her  she  did  not  support  it  with 
the  second  legs,  even  when  flying. 

Philanthus  punctatus  is  a  pretty  little  yellow-banded 
species  much  resembling  Cerceris  in  appearance.  The 
nest  consists  of  a  main  gallery  with  pockets  leading  from 
it,  each  pocket  being  stored  with  one  egg  and  enough 
bees  to  nourish  a  single  larva.  When  the  wasps  emerge 
from  the  cocoon  they  find  themselves  in  the  company  of 
their  nearest  relatives  and  in  possession  of  a  dwelling- 
place,  and  they  all  live  together  for  a  time  before  starting 
IS4 


THE    BURROWERS 

out  independently  to  seek  their  fortunes.  On  the  fifth 
of  August  we  discovered  on  the  island  a  happy  family  of 
this  kind,  consisting  of  three  brothers  and  four  sisters, 
the  females,  with  their  bright  yellow  faces  and  mandi- 
bles, being  handsomer  than  the  males.  They  seemed  to 
be  on  the  most  amicable  terms  with  each  other,  their 
only  trouble  being  that  while  they  were  all  fond  of  look- 
ing out,  the  doorway  was  too  small  to  hold  more  than  one 
at  a  time.  The  nest  was  opened  in  the  morning  at  about 
nine  o'clock,  and  during  the  next  thirty  or  forty  minutes 
their  comical  little  faces  would  appear,  one  after  an- 
other, each  wasp  enjoying  the  view  for  a  few  minutes 
with  many  twitchings  of  the  head,  and  then  retreating 
to  make  way  for  another,  perhaps  in  response  to  some 
hint  from  behind.  Then  one  by  one  they  would  come 
out,  circle  about  the  spot,  and  depart,  sometimes  leaving 
one  of  their  number  to  keep  house  all  day  alone.  They 
usually  left  the  hole  open;  but  when  there  was  a  wasp 
within,  it  was  soon  closed  from  below.  During  this 
playtime  period  they  did  not  return  until  they  were 
ready  to  settle  down  for  the  night,  the  first  one  coming 
home  at  half  after  two  or  three  o'clock,  and  the  others 
arriving  at  intervals,  none  of  them  staying  out  later  than 
five.  Most  commonly  they  found  the  right  spot  without 
trouble,  scratched  open  the  hole,  and  then  either  closed 
155 


WASPS,    SOCIAL   AND    SOLITARY 

it  behind  them  or  stood  waiting  in  the  doorway  for  the 
next  arrival;  but  occasionally  they  had  difficulty  in  locat- 
ing the  nest,  and  worked  at  two  or  three  different  places 
before  rinding  it. 

We  kept  these  wasps  under  close  observation,  often 
watching  the  nest  from  the  moment  it  was  opened  in  the 
morning  until  it  was  closed  at  night.  On  the  twelfth  of 
August,  a  week  from  the  time  that  we  first  saw  them, 
one  of  the  females  felt  the  responsibilities  of  life  settling 
down  upon  her.  At  half  after  four  in  the  afternoon  she 
began  to  enlarge  the  nest,  and  worked  with  a  great  deal 
of  energy  for  forty  minutes.  After  a  long  disappearance 
within  the  hole  she  would  come  up  backwards,  kicking 
behind  her  a  quantity  of  earth  which  was  not  only  taken 
outside,  but  was  then  spread  out  far  and  wide.  She 
worked  with  the  front  pair  of  legs,  which  were  curved 
inward,  after  the  manner  of  Bembex;  and  when  a  pebble 
or  some  such  object  came  in  her  way  she  either  dragged 
it  to  a  distance  with  her  mandibles  or  pushed  it  before 
her  with  her  head  in  a  way  quite  peculiar  to  herself.  In 
distributing  the  earth  that  was  taken  out,  she  went  five 
and  one  half  inches  from  the  nest  —  a  distance  which 
is  much  greater  than  is  common  among  wasps,  but 
which  accords  well  with  the  habits  of  punctatus,  since 
she  continues  the  work  of  excavation  from  day  to  day. 
156 


THE    BURROWERS 

On  August  thirteenth,  at  half  after  eight  in  the  morn- 
ing, we  found  that  a  second  female,  perhaps  inspired  by 
the  example  of  her  sister, 
had   made   a   new   nest 
within  two  inches  of  the 
first  one,  and  had  flown 
away,    leaving   it    open. 
Presently  the  other  wasps 
began  to  appear,  one  after 
the  other,  in  their  door- 

PHILANTHUS   PUNCTATUS 

way.   Two  of  the  males 

flew  away,  and  one  of  the  females,  doubtless  the  one 
that  we  had  seen  digging  the  night  before,  began  to 
work  afresh  at  making  the  nest  larger.  Probably  she 
was  excavating  a  pocket  for  the  reception  of  an  egg, 
and  the  amount  of  labor  required  was  ernormously  in- 
creased by  the  great  length  (about  twenty-two  inches) 
of  the  main  gallery  by  which  the  displaced  earth  must 
be  carried  out.  She  worked  for  an  hour,  and  in  spread- 
ing the  dirt  about,  inadvertently  filled  in  the  opening 
of  the  second  nest.  At  length  she  flew  away. 

At  ten  o'clock  a  female  arrived  carrying  a  bee,  and 
tried  to  find  nest  No.  2.  She  came  to  the  wrong  place, 
and  worked  about,  here  and  there,  for  some  minutes, 
holding  the  bee  under  the  thorax,  clasped  by  the  second 


WASPS,    SOCIAL   AND    SOLITARY 

pair  of  legs.  Being  unsuccessful,  she  dropped  her  burden, 
and  flew  away  for  a  few  minutes.  While  she  was  gone 
we  removed  a  leaf  that  had  fallen  over  her  nest,  and  on 
her  return  she  at  once  descended  upon  the  right  spot, 
and  began  to  scratch  open  the  entrance,  the  bee  being 
kicked  backward  with  the  rejected  earth.  When  the 
way  was  clear,  however,  she  picked  it  up,  brought  it 
toward  the  hole,  dropped  it,  ran  in  and  out,  brought  it 
nearer,  ran  in  again,  and  turning  around  in  the  tunnel, 
seized  the  bee  in  her  mandibles  and  pulled  it  down.  This 
performance  was  due  to  the  accidental  obstruction  of 
the  gallery,  for  we  afterward  found  that  punctatus 
ordinarily  flies  directly  into  her  nest,  or,  when  it  is 
closed,  pauses  on  the  wing  to  scratch  an  opening  with 
the  first  legs.  The  bee  is  pushed  backward  a  little  as 
she  goes  in,  but  does  not  often  project  from  under  her 
abdomen. 

At  fifteen  minutes  after  ten  the  worker  from  nest  No.  i 
brought  in  a  bee,  and  from  that  time  the  two  worked 
industriously.  They  showed  some  individuality  in  their 
ways,  for  No.  2  always  closed  her  door  when  she  went 
away,  and  never  circled  at  all,  while  No.  i  invariably 
circled  before  leaving,  and  always  left  her  nest  open. 
To  be  sure,  there  was  a  female  left  on  guard,  so  that  per- 
haps she  did  not  feel  the  need  of  caution. 
158 


THE    BURROWERS 

Our  wasps  had  not  far  to  go  for  their  victims.  Forty 
feet  away,  on  the  eastern  side  of  the  island,  was  a  steep 
declivity,  and  here,  in  the  soft  crumbly  soil,  was  a  great 
Halictus  settlement.  No  prettier  sight  can  be  imagined 
than  is  presented  by  this  colony  on  every  sunny  summer 
day.  The  whole  bank  is  riddled  with  nests,  and  at  the 
entrance  of  each  stands  a  female  bee,  her  tiny  head  ex- 
actly filling  the  opening.  The  bees  are  constantly  arriv- 
ing, laden  with  pollen,  whereupon  the  sentinels  politely 
back  inward  to  make  way  for  them.  Into  this  scene  of 
contented  industry  descends  the  ravaging  Philanthus, 
taking  guards  and  workers  alike. 

On  the  afternoon  of  the  fourteenth  of  August  our  two 
wasps  were  in  the  full  tide  of  affairs.  No.  i  took  in  eleven 
bees  within  two  hours,  but  her  record  was  somewhat 
confused,  as  two  other  females  were  going  in  and  out  at 
the  same  time.  We  felt  sure  that  neither  of  these  was 
hunting,  but  one  of  them  shared  in  the  labor  of  the  nest 
by  helping  with  the  work  of  excavation. 

No.  2,  however,  was  alone,  so  that  we  could  keep  a 
definite  account  of  her  comings  and  goings.  We  watched 
her  from  half  past  one  until  five,  at  which  hour  she 
came  home  without  a  load,  and  at  once  closed  the  nest 
for  the  night,  after  having  stored  thirteen  bees  in  three 
hours  and  nine  minutes.  In  some  cases  the  capture  of 
159 


WASPS,    SOCIAL   AND    SOLITARY 

the  bee  occupied  only  one,  two,  or  three  minutes,  while 
at  other  times  she  was  gone  much  longer.  At  each  return 
she  stayed  only  an  instant  —  just  long  enough  to  de- 
posit the  bee  —  inside  the  nest,  and  then  spent  a  minute 
in  carefully  closing  the  hole.  The  wasps  that  were  going 
in  and  out  of  nest  No.  i  sometimes  closed  it  when  they 
went  away,  but  this  was  done  in  an  untidy  fashion,  quite 
different  from  the  nicety  and  precision  of  No.  2. 

At  half  after  five  o'clock  the  wasp  that  had  been  dig- 
ging for  some  little  time  at  nest  No.  i  flew  to  nest  No.  2, 
opened  it,  and  attempted  to  enter,  but  was  quickly 
driven  out  by  the  owner.  She  then  dug  a  little  in  several 
other  places,  finally  returning  to  sleep  in  the  family 
home.  On  the  next  day  we  found  that  No.  2  was  tolerat- 
ing in  her  nest  one  of  the  females  that  had  not  yet  begun 
to  hunt,  but  whether  it  was  the  one  she  had  rejected  the 
night  before  or  the  fourth  member  of  the  sisterhood,  we 
could  not  tell.  On  the  eighteenth,  three  days  later,  the 
wasp  had  left  this  temporary  home  and  made  a  nest  for 
herself  four  feet  away  on  the  hillside.  The  males  were 
still  living  in  the  first  nest  with  two  females. 

When  the  weather  was  cold  and  cloudy  punctatus 

remained  closely  housed  within  the  nest,  or,  at  most, 

came  out  to  do  an  hour's  digging,  and  then  disappeared. 

The  warmer  the  weather,  and  the  more  brilliant  the 

160 


THE    BURROWERS 

sunshine,  the  more  rapidly  they  worked.  When  leaving 
the  nest  they  would  often  creep  out  and  walk  around 
it  three  or  four  times  before  rising  on  their  wings,  and 
even  then  would  sometimes  alight  once  or  twice  before 
flying  away.  The  males,  especially,  liked  to  stand  about 
for  a  time,  watching  their  more  industrious  sisters  at 
their  work.  The  females  usually  began  the  day  with  dig- 
ging, and  frequently  closed  it,  toward  night,  in  the  same 
way. 

In  order  to  see  the  method  of  stinging,  we  at  one  time 
provided  ourselves  with  a  number  of  bees,  and  putting 
one  of  them  into  a  bottle,  introduced  a  wasp.  She  seized 
it  almost  immediately,  with  great  vigor,  and  stung  it 
once,  under  the  neck,  and  then  dragged  it  up  and  down 
the  bottle  by  one  antenna  which  was  held  in  the  man- 
dibles. After  a  moment  she  shifted  it  and  held  it  with 
the  second  legs  in  the  usual  way.  We  now  put  in  another 
bee,  which  she  also  caught,  stung  in  the  same  place,  and 
then  dropped  without  relaxing  her  hold  of  the  first  one. 
As  she  seemed  to  have  nothing  further  to  show  us  we 
released  her,  and  after  circling  a  little  she  took  into  her 
nest  the  bee  that  she  was  carrying. 

In  our  next  experiment  we  used  a  larger  glass,  thinking 
that  with  more  space  we  might  see  malaxation.  The 
instant  that  the  wasp  was  introduced  she  grasped  the 
161 


WASPS,    SOCIAL   AND    SOLITARY 

bee  with  one  rapid  powerful  motion,  and  stung  it  just 
under  the  neck  as  before.  Then  holding  it  with  the 
second  legs  she  began  to  fly  about  in  the  glass.  We  now 
introduced  another  bee,  whereupon  the  first  one  was 
relinquished,  and  the  second  was  treated  in  exactly  the 
same  way.  The  stinging  was  the  beginning  and  the  end 
of  the  operation,  and  when  we  released  her  she  at  once 
took  the  bee  into  the  nest.  There  was  no  malaxation 
outside,  and  certainly  there  was  none  within,  as  was 
shown  by  the  rapidity  with  which  the  wasps  issued  from 
the  nest  after  storing  the  bees.  We  were  successful  in 
getting  the  wasps  to  sting  only  when  we  tried  the  experi- 
ment with  those  that  were  hunting.  When  those  that  had 
not  yet  begun  to  store  their  nests  were  put  into  the  glass 
they  paid  no  attention  to  the  bees. 

The  victim  of  the  sting  of  punctatus  is  killed  at  once. 
Life  is  extinct  from  the  instant  that  the  stroke  is  given. 
This  is  true  also  of  the  honey-bee  that  is  the  victim  of 
Fab  re's  Philanthus  apivorus;  but  the  explanation  that 
he  gives  of  the  action  of  his  wasp  in  thus  dealing  sudden 
death  instead  of  paralyzing  its  foe  —  that  the  honey 
must  be  sucked  out  of  the  bee  before  it  can  be  safely  used 
as  food  for  the  larva  —  does  not  hold  good  in  our  case, 
since  the  honey  that  Halictus  carries  to  mix  with  the 
pollen  upon  which  her  offspring  are  fed,  is  not  removed. 
162 


THE    BURROWERS 

As  time  went  on  we  found  on  the  island  two  other 
Philanthus  colonies,  although  that  is  rather  too  large  a 
word  to  apply  to  them,  since  one  consisted  of  four  nests 
and  the  other  of  only  two.  When  we  came  to  excavate 
the  nests  of  this  species  we  were  greatly  astonished  at 
the  length  of  the  gallery,  and  not  until  then  did  we  prop- 
erly appreciate  the  industry  of  these  little  wasps.  It  is 
no  small  undertaking  to  follow  one  of  their  tunnels  for 


NEST   OF    PHILANTHUS    PUNCTATUS 

A-B,  3J  inches;   B-C,  5  inches;   C-D,  14  inches; 
D-E,  8  inches 

twenty-two  inches,  even  when,  as  in  this  case,  the  greater 
part  of  it  is  parallel  to  the  surface  of  the  ground.  We 
did  not  find  distinct  pockets,  as  the  soil  was  very  crumbly 
and  fell  in  as  we  worked,  but  we  came  upon  clumps  of 
bees  an  inch  or  so  to  one  side  of  the  gallery  and  about 
three  inches  apart,  with  larvae  in  different  stages  of 
development.  In  one  nest  we  found  twenty-six  bees  in 
163 


WASPS,    SOCIAL   AND    SOLITARY 

two  clumps,  some  of  them  half-eaten,  and  some  of  them 
fresh,  but  all  quite  dead.  We  have  no  doubt  that  punc- 
tatus  completely  provisions  one  pocket  and  closes  the 
opening  from  it  into  the  gallery,  before  she  starts  an- 
other, making  a  series  of  six  or  eight  independent  cells. 
The  provision  for  one  larva  is  probably  twelve  or  four- 
teen bees,  the  capture  of  which,  in  good  weather,  would 
be  a  fair  day's  work. 

That  the  males  do  not  always  stay  on  in  their  ancestral 
home  is  shown  by  an  observation  that  we  made  on  the 
only  occasion  that  we  ever  saw  this  species  in  our  garden. 
Nothing  was  stirring  at  half  past  three  o'clock  in  the 
afternoon,  and  we  had  given  up  work  and  started  for 
home,  when,  in  going  up  an  inclined  part  of  the  field, 
we  noticed  something  in  motion  within  a  ragged- edged 
hole  which  ran  obliquely  into  the  ground.  It  seemed 
strange  that  a  wasp  should  be  beginning  its  nest  at  so 
late  an  hour;  but  a  wasp  it  was,  as  we  could  plainly  see 
when  we  took  an  attitude  sufficiently  humble.  It  was 
loosening  the  earth  with  its  mandibles,  and  then  pushing 
it  backward  with  its  hind  legs  and  abdomen.  We  had 
scarcely  settled  down  to  watching  it  when  a  second  one 
of  the  same  species  appeared,  and  with  a  good  deal  of 
fuss  and  flutter  began  to  dig  its  hole  close  by.  The  spot 
chosen  by  this  second  one  proved  unsatisfactory,  and 
164 


THE    BURROWERS 

another  beginning  was  made  in  a  new  place.  Again 
something  was  wrong,  nor  was  a  third  choice  any  better. 
At  last,  however,  the  work  was  started  in  earnest,  and 
might  have  been  carried  to  a  conclusion  if  we  had  not 
caught  the  little  creature  to  satisfy  a  suspicion  that  had 
been  growing  in  our  minds.  Yes,  we  were  right.  The 
worker  was  not  a  female  making  a  nest  for  the  rearing 
of  her  young,  but  a  male  punctatus,  preparing  a  shelter 
for  the  night. 

In  the  mean  time  the  first  wasp  had  pushed  back  such 
a  quantity  of  earth  that  the  hole  was  entirely  closed,  but 
every  few  minutes  he  came  backing  out  to  clear  the  way. 
At  the  end  of  half  an  hour  all  became  quiet.  The  door 
remained  closed,  and  doubtless  the  wasp  was  fast  asleep. 
Putting  a  blade  of  grass  and  then  an  inverted  tumbler 
over  the  nest,  we  left  him  for  the  night. 

On  removing  the  glass  at  half  past  seven  the  next 
morning,  we  found  the  nest  open  but  the  wasp  not  visi- 
ble. At  half  past  eight  the  head  appeared  just  inside  the 
hole,  the  long  antennae  twitching  now  to  this  side,  now 
to  that,  as  if  an  inspection  were  being  made.  Soon  the 
head  came  out.  The  wasp  stood  for  some  minutes  mak- 
ing a  survey,  looking  to  right  and  left  with  lively  jerks 
of  the  body.  Then,  apparently  concluding  that  the  day 
was  not  far  enough  advanced,  he  came  out,  whirled 
165 


WASPS,    SOCIAL   AND    SOLITARY 

around,  and  ran  head-first  into  the  nest.  He  probably 
took  another  nap,  for  all  was  quiet  until  just  before  ten 
o'clock,  when  the  antennae  appeared  again.  The  survey 
was  taken  as  before,  first  from  within  and  then  with  the 
head  in  view.  At  last  he  flew  out,  and  making  three 
circles,  each  one  wider  than  the  last,  about  the  place, 
flew  away.  He  stayed  out  all  day,  and  had  not  returned 
at  half  past  three  in  the  afternoon ;  but  on  going  down 
at  half  past  four  we  found  that  he  had  gone  in  and  closed 
the  door  from  below. 

It  is  clear,  then,  that  these  males  do  not  construct  a 
new  lodging  every  night,  but  return  to  the  same  spot  to 
sleep.  Other  wasps  creep  into  crevices.  We  have  often 
found  them,  in  the  morning,  in  the  holes  of  the  posts  of 
our  cottage  porch;  but  we  are  glad  to  be  able  to  put  it 
down  to  the  credit  of  one  male  that  he  has  sufficient 
foresight  and  industry  to  provide  a  sleeping-place,  and 
sufficient  intelligence  to  return  to  the  spot  when  the  de- 
clining sun  warns  him  that  evening  is  approaching. 

While  punctatus  was  in  the  height  of  its  activity  we 
found  another  species,  P.  ventilabris,  taking  bees  of 
several  genera  and  species  into  a  ground  nest.  She  also 
carried  her  prey  with  her  second  pair  of  legs,  and  when- 
ever she  left  her  nest  she  closed  the  door.  She  was  a 
shy  little  thing,  and  did  not  approve  of  our  interest  in 
166 


THE    BURROWERS 

her.  At  one  time,  being  startled  by  some  movement  on 
our  part,  she  dropped  her  load  and  flew  away.  We  placed 
the  bee  upon  the  closed  nest,  and  when  she  came  back 
with  another,  she  paused  and  looked  at  it,  took  in  the 
one  she  was  carrying,  and  then  returned  for  number 
one.  This  was  placed  on  the  threshold  while  she  entered 
and  turned  around,  and  was  then  pulled  in.  Some  wasps, 
notably  C.  ornata  and  our  little  tornado,  refuse  to  take 
in  their  prey,  even  if  they  have  caught  it  themselves, 
excepting  in  a  regular  succession  of  events;  and  thus  the 
more  reasonable  conduct  of  ventilabris  gains  in  interest. 
To  the  west  of  Milwaukee,  across  the  valley  of  the 
Menominee,  rises  a  sandy  hilltop  which  is  a  little  insect 
kingdom  by  itself.  Ants  of  course  abound,  and  the  gentle 
little  solitary  bees,  with  their  loads  of  pollen,  may  be 
seen  everywhere,  seeming  to  melt  into  the  ground,  so 
quickly  and  quietly  do  they  open  their  burrows.  Here 
Oxybelus  plys  her  trade  of  fly-catching,  and  graceful 
Ammophila  dances  with  her  shadow  over  the  sunny 
ground,  while  Cerceris  rests  in  her  doorway  with  an  air 
of  leisurely  superiority  to  the  vulgar  cares  of  life ;  and 
here,  one  day  in  early  July,  a  sudden  access  of  energy 
seemed  to  strike  Aphilanthops  frigidus,  a  wasp  which 
we  had  found  a  year  before  taking  in  the  wingless  queens 
of  ants.  All  at  once  they  were  digging  everywhere,  biting 
167 


WASPS,    SOCIAL   AND    SOLITARY 

and  scratching  with  great  energy,  and  soon  disappearing 
in  the  depths  of  their  sandy  tunnels.  So  deep  is  their 
primary  gallery  that  even  in  this  easy  medium  it  takes 
them  the  best  part  of  a  day  to  get  it  ready  for  storing; 
but  once  finished  it  doubtless  serves  as  a  home  through 
the  season.  It  has  at  the  entrance  a  little  cup-shaped 
vestibule  where  the  wasp  drops  the  ant  as  she  enters, 
running  out  of  sight  herself,  and  then,  after  she  has 
turned  around,  coming  back  to  pull  it  within.  This  nest 
is  a  very  difficult  one  to  excavate  neatly,  as  the  sand  falls 
at  the  slightest  touch. 

A  day  or  two  after  we  had  seen  frigidus  making  her 
residential  arrangements,  we  found  twenty-five  or  thirty 
within  a  few  feet  of  each  other,  working  with  great  ardor 
at  carrying  in  queens,  the  doors  being  left  closed  or  open 
according  to  individual  judgment.  The  steadiest  work- 
ers brought  one  every  forty  minutes,  scarcely  pausing 
inside  the  nest,  but  others  made  long  stays  within,  leav- 
ing the  door  closed.  The  ants  were  carried  under  the 
body  with  all  the  legs  folded  around  them,  but  they 
were  heavy  things,  and  were  often  dropped  as  the  wasp 
flew  across  the  field,  giving  opportunities  for  robbery 
that  were  promptly  taken  advantage  of.  We  picked  up 
one  of  these  ants  and  placed  it  in  the  doorway  of  a  wasp 
that  had  just  gone  in.  She  came  up  twice,  looked  at  it, 
168 


<^"^:~^^<^':'^ 


APHILANTHOPS    GATHERING   ANTS 


THE   BURROWERS 

and  backed  down  again;  but  the  third  time  she  first 
touched  it,  then  seized  it  and  took  it  below.  From  an- 
other wasp  that  was  just  entering  we  took  the  ant  she  had 
dropped  and  moved  it  half  an  inch  away.  When  she 
had  turned  and  come  up  for  it,  she  seemed  surprised, 
came  out  and  looked  about,  found  it  and  dropped  it  in 
the  doorway,  going  in  herself  to  turn  around  as  before. 
We  seized  this  chance  to  move  it  again,  and  again  she 
came  out,  found  it,  took  it  back,  and  dropped  it.  This 
was  repeated  five  times,  but  when  she  took  it  in  for  the 
sixth  time,  after  dropping  it,  she  whirled  around  and 
picked  it  up  so  quickly  that  our  malice  was  foiled. 

We  were  puzzled  by  the  actions  of  a  wasp  that  ap- 
proached her  nest  again  and  again,  but  always  circled 
away  without  entering,  until  looking  closely  we  saw  that 
she  was  pursued  by  two  tiny  flies.  When  she  alighted 
and  walked  about  awhile  with  her  ant  tucked  under 
the  third  leg  on  one  side,  the  flies  alighted  also  and 
walked  about  behind  her.  In  the  end  she  evaded  them 
by  a  sudden  drop  into  her  hole. 

A  wasp  now  came  circling  along  with  an  ant  in  her 
grasp,  and  settled  down  between  two  small  weeds  that 
grew  about  four  inches  apart.  She  stood  quiet  a  mo- 
ment and  then  began  to  dig,  but  had  evidently  struck 
the  wrong  spot,  for  after  a  moment  she  moved  and  tried 
171 


WASPS,    SOCIAL   AND    SOLITARY 

another  place.  Not  finding  the  entrance,  she  rose  and 
flew  close  under  one  of  the  plants  and  began  to  scratch 
again,  but  still  in  vain.  For  ten  minutes  she  persisted, 
keeping  within  a  few  inches  of  the  spot,  and  holding  on 
to  the  ant  all  the  time,  although  it  was  dreadfully  in  her 
way  as  she  walked  about.  Then  she  dropped  it  and  began 
to  dig  more  vigorously,  dividing  her  attention  between 
the  two  spots  she  had  attempted  at  first.  She  seemed 
troubled  at  having  to  leave  the  ant,  and  often  picked  it 
up  and  tried  to  hold  it  while  she  worked.  Once  in  a 
while  she  would  take  it  with  her,  and  after  circling 
about  the  spot  would  disappear,  but  in  a  few  minutes 
she  would  return.  It  seemed  to  us  that  two  little  plants 
growing  near  together  must  have  been  her  landmarks, 
and  that  probably  she  had  been  deceived  by  the  like- 
ness that  those  before  us  bore  to  the  ones  near  her  nest. 
Again  and  again  she  seemed  to  hesitate  and  think  the 
matter  over,  but  gradually  one  of  the  holes  absorbed 
her  more  and  more.  At  the  end  of  an  hour  she  was  out 
of  sight  in  it,  and  had  carried  her  ant  down,  although 
she  was  still  kicking  out  sand.  It  was  evident  that  her 
memory  had  played  her  false,  and  that  she  had  either 
covered  her  hole  so  neatly  that  she  could  not  find  the 
spot  herself,  or  had  missed  the  place  entirely.  She  had 
accommodated  herself  to  circumstances  pretty  well, 
172 


THE  BURROWERS 

although  she  ought  to  have  realized  earlier  that  it  would 
be  easier  to  dig  one  nest  than  two. 

We  now  tried  to  excavate  a  nest,  but  could  not  follow 
the  tunnel,  although  we  found  clumps  of  ants  at  differ- 
ent levels,  some  with  larvae  feeding  on  them.  The  deep- 
est were  eighteen  inches  down.  Hoping  to  secure  a  guide, 
we  borrowed  an  ant  as  it  was  dropped  in  the  doorway 
and  tied  a  thread  to  it.  The  wasp  pulled  it  in  and  took 
it  part  way  down  with  this  attachment ;  but  before  any 
great  depth  was  reached,  the  thread  was  seemingly 
bitten  off,  as  we  found  the  free  end  without  the  ant. 
A  second  attempt  brought  no  better  results. 

So  long  as  we  were  quiet  the  wasps  did  not  notice  us, 
but  after  being  disturbed  they  became  shy  and  circled 
about  a  good  deal  before  entering.  Some  of  the  ants 
were  completely  paralyzed,  while  others  moved  their 
abdomens,  legs,  and  mouth  parts.  All  through  the  morn- 
ing, the  whole  place  was  in  a  bustle,  but  when  we  came 
back,  after  eating  our  luncheon  in  a  shady  spot,  quiet 
reigned;  the  colony  seemed  asleep,  and  although  we 
waited  for  an  hour  not  a  wasp  showed  herself. 

The  ants  that  these  wasps  were  bringing  all  had  wings. 

The  European  genus  Fertonius  takes  worker  ants  which 

can  be  picked  up  anywhere;  but  so  far  as  we  know, 

these  queens  leave  the  nest  only  at  the  time  of  their 

173 


WASPS,    SOCIAL   AND    SOLITARY 

nuptial  flight,  after  which  the  wings  are  lost.  How  then 
are  they  captured  ?  Can  it  be  that  the  wasps,  though  not 
much  larger  than  their  prey,  descend  into  the  home  of 
the  ants,  bearding  the  lions  in  their  den,  and  carrying 
off  their  young  queens  by  force  of  arms  ?  This  smacks 
of  heroism. 

Much  interested  in  the  matter,  we  carefully  examined 
the  ant-hills  of  the  neighborhood.  Those  on  top  of  the 
hill  had  openings  too  small  to  admit  frigidus,  supposing 
she  had  wanted  to  enter,  but  down  on  the  roadside  below 
we  found  some  larger  doorways  and  sat  down  beside 
them.  We  had  scarcely  arrived  when  a  frigidus  appeared 
on  the  scene,  alighting  six  feet  away.  That  she  should 
have  come  hunting  so  soon  seemed  almost  too  good  to 
be  true,  but  she  certainly  was  not  doing  anything  else. 
She  did  not  dig,  nor  feed  on  the  clover,  nor  circle  about 
as  though  looking  for  her  nest,  but  began  to  clean  and 
brush  herself  assiduously.  Then  she  climbed  a  tall  grass 
blade,  and  swinging  at  the  top  went  through  some  curi- 
ous gymnastic  performances.  Then  she  brushed  herself 
again,  drawing  her  third  legs  over  the  sides  of  her  abdo- 
men. This  went  on  from  moment  to  moment,  until  half 
an  hour  had  passed,  and  more  than  once  the  painful 
suspicion  crossed  our  minds  that  this  was  some  trifling 
male  putting  in  the  hours  between  breakfast  and 
174 


THE   BURROWERS 

luncheon.  One  encouraging  fact  cheered  us :  aimless 
as  the  wasp  appeared  she  was  slowly  drawing  nearer 
and  nearer  to  the  nest ;  and  at  last,  alighting  on  the  top 
of  a  weed  close  by,  she  crouched  there  in  a  most  peculiar 
attitude,  and  gazed  intently  at  the  opening.  Absorbed 
and  tense,  she  looked  about  to  leap  upon  her  prey;  but 
after  a  time  she  relaxed  and  moved  about  a  little.  Pre- 
sently she  came  close  to  the  entrance  and  seemed  on  the 
point  of  going  in;  but  the  ants  were  swarming  up  and 
down,  and  we  thought  that  perhaps  that  step  required 
more  courage  than  she  possessed.  At  any  rate,  she  did 
not  enter,  but  hung  about  for  some  minutes  and  then 
flew  away. 

Was  this  a  young  wasp  out  on  her  first  hunt  ?  What 
strange  antiphonal  desires  must  have  stirred  at  the  sight 
of  the  nest,  and  how  mysterious  was  the  power  that  drew 
her  to  it !  Was  there  in  her  brain  any  image  of  the  queen 
she  must  seek  and  sting  and  carry  away  from  among 
her  guards  and  subjects  ?  Or  had  she  perhaps  already 
achieved  the  adventure,  and  did  the  memory  of  the 
bitter  nips  that  little  ant  jaws  can  give  make  it  a  harder 
task  than  it  was  the  first  time,  when  she  risked  the  ills  she 
knew  not  of  ?  That  she  hesitated  and  carried  on  the 
work  reluctantly  seemed  to  show  that  her  flesh  was 
weak  and  needed  the  prick  of  conscience  to  drive  it  on. 
175 


WASPS,    SOCIAL   AND    SOLITARY 

Had  we  here  then  the  small  beginnings  of  moral  sense 
and  perception  of  duty  ?  Can  it  be  that  of  such  humble 
origin  is  the  power  that  "doth  preserve  the  stars  from 
wrong"? 

We  went  on  with  these  meditations  for  several  days 
while  lingering,  with  gradually  diminishing  hopefulness, 
over  one  ant-hill  after  another.  The  wasps  were  carrying 
in  winged  queens  by  the  score,  but  they  did  not  come 
our  way  to  find  them ;  and  although  we  ranged  about 
widely,  we  failed  to  see  the  capture.  Occasionally  we 
met  a  frigidus  hunting,  running  about  on  the  ground 
and  poking  her  head,  not  only  into  ant  holes,  but  into 
holes  of  all  sorts,  and  as  we  sometimes  saw  young  queens 
(wingless  however)  starting  to  dig  their  nests,  we  thought 
these  might  be  the  object  of  the  search.  The  weather 
was  cold  and  windy,  most  unpropitious  for  swarming, 
and  yet  frigidus  was  working  as  briskly  as  ever;  so  that 
we  began  to  feel  sure  that  she  could  not  depend  upon 
meeting  the  queens  outside  the  nest,  but  must  enter  to 
get  them.  Just  as  this  point  we  received  a  letter  from 
Mr.  William  M.  Wheeler,  well  known  as  an  authority  on 
ants,  saying"  that  he  felt  very  sure  that  the  wasp  could 
not  extract  the  queens  from  the  nest,  but  must  find  them 
running  on  the  ground,  just  after  the  nuptial  flight, 
before  they  dug  their  holes  and  started  their  colonies. 
176 


THE  BURROWERS 

Respecting  this  opinion,  but  still  feeling  unconvinced, 
we  caught  a  wasp  in  a  glass,  and  carrying  it  to  an  ant- 
hill, inverted  it  so  that  she  was  confined  just  over  the 
entrance.  After  buzzing  up  and  down  for  a  moment,  she 
alighted  and  walked  calmly  into  the  hole  ;  but  a  fraction 
of  a  second  later  she  came  rushing  madly  out  again, 
pursued  by  the  most  furious  lot  of  ants  that  ever  de- 
fended the  home  city  against  invasion.  Down  tumbled 
our  air  castles  about  courage  and  duty,  for  however 
frigidus  gets  her  queens,  it  is  not  in  that  way.  We  have 
not  yet  seen  the  meeting  and  the  capture,  but  hope  that 
sometime  we  may  be  lucky  enough  to  be  on  the  right 
spot  at  the  right  time. 


Chapter  VIII 

THE  WOOD-BORERS 

OUR  two  species  of  Trypoxylon  are  both  slender- 
waisted  black  wasps,  albopilosum  having  bunches 
of  snowy  white  hairs  on  the  first  legs,  and  measuring 
three  quarters  of  an  inch  in  length,  while  rubrocinctum 
is  a  little  smaller,  and,  as  the  name  implies,  wears  a  red 
girdle. 

Although  these  wasps  are  called  wood-borers,  they 
will  use  convenient  cavities  in  any  material.  When  we 
went  out  to  our  summer  cottage,  in  the  last  days  of  June, 
1895,  we  found  many  little  wasps  of  the  species  Trypo- 
xylon rubrocinctum  busily  working  about  a  brick  smoke- 
house on  the  place.  Closer  examination  showed  that  in 
the  mortar  between  the  bricks  were  many  little  openings 
leading  back  for  a  considerable  distance,  which  were 
occupied  by  the  wasps.  It  would  seem  that  these  holes 
were  excavated  by  some  other  agency  than  the  wasps 
themselves,  as  they  were  so  much  too  deep  for  their  pur- 
poses that  before  using  them  they  built  a  mud  partition 
178 


THE   WOOD-BORERS 

across  the  opening  about  an  inch  from  the  outside  of  the 
wall.  Later  we  found  nests  of  the  same  species  in  the 
posts  which  support  an  upper  balcony  of  the  cottage; 
and  here,  too,  the  wasps  made  use  of  holes  which  were 
already  excavated. 

In  the  following  summer  we  found  large  numbers  of 
these  wasps  at  work  in  a  straw-stack.  The  stack  had 
been  cut  off  perfectly  smooth  on  one  side,  so  that  many 
thousands  of  the  cut  ends  of  the  straws  were  exposed 
to  view,  and  these  proved  very  attractive  to  rubrocinc- 
tum.  This  species  is  very  cosmopolitan  in  its  tastes,  for 
we  found  it  utilizing  the  small  holes  in  the  sticks  of 
a  woodpile.  The  straws  made  the  daintiest  nesting- 
places,  however,  and  were  well  adapted  to  our  purposes, 
since  they  could  be  drawn  out  of  the  stack  and  split 
lengthwise  so  that  the  contents  could  be  easily  studied. 
The  two  halves  could  then  be  brought  together  again 
without  injuring  the  inhabitants,  and  thus  we  often 
kept  several  sets  under  observation  long  enough  to 
watch  the  changes  from  the  egg  to  the  pupa.  We  found 
Trypoxylon  albopilosum  nesting  in  holes  made  by  beetles 
in  posts  and  trees,  but  never  in  straws.  A  third  species, 
bidentatum,  was  very  common,  nesting  in  the  stems 
of  plants.  During  the  month  of  August  we  saw  many 
individuals  of  this  species  hunting  for  spiders  on  the 
179 


WASPS,    SOCIAL   AND    SOLITARY 

blackberry  bushes ;  but  at  this  time  we  were  so  much 
absorbed  in  Crabro  stirpicola  that  we  never  followed 
them  to  their  homes. 

Rubrocinctum  was  more  conveniently  studied,  and 
through  July  and  August  we  watched  the  comings 
and  goings  of  these  little  wasps.  They  were  very  good- 
tempered,  never  resenting  our  close  proximity  nor  our 
interference  with  their  housekeeping.  By  working  hard 
they  could  prepare  a  nest,  store  it  with  spiders,  and  seal 
it  up  all  in  the  same  day.  This  we  have  seen  them  do  in 
several  instances.  In  other  cases  the  same  operation 
takes  three  or  four  days.  In  the  second  summer  that  we 
worked  with  them  we  found  one  very  energetic  mother 
that  stored  four  nests  in  one  day.  It  had  rained  hard 
on  the  twenty-sixth  of  July,  and  no  wasp  works  in  such 
weather.  On  the  afternoon  of  the  twenty-seventh  we 
took  a  straw  just  as  the  little  mother  was  bringing  in  a 
spider.  We  opened  it  and  found  that  the  innermost  cell 
contained  eight  Epeirids,  with  an  egg  on  the  abdomen 
of  the  last  one  taken  in;  the  second  cell  was  provisioned 
with  ten  spiders,  with  the  egg  on  the  seventh,  so  that 
three  had  been  brought  in  after  it  was  laid;  the  third 
cell  had  the  egg  on  the  last  spider,  as  did  also  the  fourth. 
All  of  these  eggs  hatched  on  the  twenty-ninth,  —  the  two 
outer  ones,  that  were  laid  last,  between  eight  and  nine 
180 


THE   WOOD-BORERS 

o'clock  in  the  morning,  and  the  two  that  were  laid  earlier 
between  two  and  three  in  the  afternoon.  This  was  the 
biggest  day's  hunting  that  we  have  ever  recorded  for  any 
of  our  wasps. 

With  both  species  (T.  rubrocinctum  and  T.  albopilo- 
sum),  when  the  preliminary  work  of  clearing  the  nest 
and  erecting  the  inner  partition  has  been  performed  by 
the  female,  the  male  takes  up  his  station  inside  the  cell, 
facing  outward,  his  little  head  just  filling  the  opening. 
Here  he  stands  on  guard  for  the  greater  part  of  the  time 
until  the  nest  is  provisioned  and  sealed  up,  occasionally 
varying  the  monotony  of  his  task  by  a  short  flight.  As 
a  usual  thing  all  the  work  is  performed  by  the  female, 
who  applies  herself  to  her  duties  with  greater  or  with 
less  industry  according  to  her  individual  character ;  but 
the  male  doubtless  discharges  an  important  office  in 
protecting  the  nest  from  parasites.  We  have  frequently 
seen  him  drive  away  the  brilliant  green  Chrysis  fly, 
which  is  always  waiting  about  for  a  chance  to  enter  an 
unguarded  nest.  On  these  occasions  the  defense  is  car- 
ried on  with  great  vigor,  the  fly  being  pursued  for  some 
distance  into  the  air.  There  are  usually  two  or  three 
unmated  males  flying  about  in  the  neighborhood  of  the 
nests,  poking  their  heads  into  unused  holes,  and  occa- 
sionally trying  to  enter  one  that  is  occupied,  but  never, 
181 


WASPS,    SOCIAL    AND    SOLITARY 

so  far  as  we  have  seen,  with  any  success,  the  male  in 
charge  being  always  quite  ready  and  able  to  take  care 
of  his  rights.  The  males,  however,  made  no  objection 
when  strange  females  entered  the  nest,  as  they  sometimes 
did  by  mistake,  nor  did  the  females  object  to  the  en- 
trance of  a  strange  male  when  the  one  belonging  to  the 
nest  happened  to  be  away ;  but  in  such  cases  the  rightful 
owner,  on  his  return,  quickly  ejected  the  intruder.  We 
often  amused  ourselves,  while  we  were  watching  the 
nests,  by  approaching  the  little  male,  as  he  stood  in  his 
doorway,  with  a  blade  of  grass.  He  always  attacked  it 
valiantly,  and  sometimes  grasped  it  so  tightly  in  his 
mandibles  that  he  could  be  drawn  out  of  the  nest  with  it. 

When  the  female  returns  to  the  nest  with  a  spider  the 
male  flies  out  to  make  way  for  her,  and  then  as  she  goes  in 
he  alights  on  her  back  and  enters  with  her.  When  she 
comes  out  again  she  brings  him  with  her,  but  he  at  once 
reenters,  and  then,  after  a  moment,  comes  out  and  backs 
in,  so  that  he  faces  outward  as  before. 

In  one  instance,  with  rubrocinctum,  where  the  work 
of  storing  the  nest  had  been  delayed  by  rainy  weather, . 
we  saw  the  male  assisting  by  taking  the  spiders  from 
the  female  as  she  brought  them  and  packing  them  into 
the  nest,  leaving  her  free  to  hunt  for  more.  This  was  an 
especially  attentive  little  fellow,  as  he  guarded  the  nest 
182 


THE   WOOD-BORERS 

almost  continuously  for  four  days,  the  female  sometimes 
being  gone  for  hours  at  a  time.  On  the  last  day  he  even 
revisited  the  nest  three  or  four  times  after  it  had  been 
sealed  up. 

It  is  upon  the  female  that  the  heaviest  part  of  the 
work  devolves.  As  soon  as  she  has  put  the  nest  in  order 
she  begins  the  arduous  task  of  catching  spiders  where- 
with to  store  it.  It  usually  takes  her  from  ten  to  twenty 
minutes  to  find  a  spider  and  bring  it  home,  but  she  is 
sometimes  absent  for  a  much  longer  time.  When  the 
spider  has  been  carried  to  the  nest  the  process  of  pack- 
ing it  in  begins.  This  occupies  some  time,  and  appar- 
ently a  good  deal  of  strength,  —  the  female  pushing  it 
into  place  with  her  head,  totally  disregarding  its  com- 
fort, all  the  spiders  that  are  caught  being  pressed  and 
jammed  together  into  a  compact  mass.  While  she  is 
busied  in  this  way  she  makes  a  loud  cheerful  humming 
noise.  The  number  of  spiders  brought  seems  to  depend 
upon  their  size,  in  which  quality  they  vary  greatly,  the 
largest  ones  being  six  or  eight  times  as  large  as  the  small- 
est. Rubrocinctum  fills  her  nest  with  from  seven  to  four- 
teen, while  the  larger  albopilosum  brings  as  many  as 
twenty-five  or  thirty.  Those  that  we  examined  repre- 
sented many  different  genera,  and  even  different  fami- 
lies, although  they  were  usually  orb-weavers. 
183 


WASPS,    SOCIAL   AND    SOLITARY 

In  a  number  of  cases,  during  the  first  summer,  after 
several  spiders  had  been  stored,  we  gently  drew  them 
out  with  a  bent  wire.  In  one  nest  in  which  there  were 
five  spiders,  we  found,  two  hours  after  they  had  been 
stored,  that  three  were  alive  and  two  were  dead.  In  an- 
other, which  the  wasp  had  just  begun  to  seal  up,  were 
ten  spiders.  Three  of  these  were  injured  in  being  drawn 
out.  Of  the  remainder  four  were  alive  and  three  dead. 
On  the  anterior  part  of  the  dorsum  of  one  of  the  living 
spiders  was  the  egg.  It  had  probably  been  fertilized  as 
the  female  carried  the  male  into  the  nest  on  her  back. 

When  we  discovered  rubrocinctum  in  the  straw-stack, 
we  made  many  observations  as  to  the  position  of  the 
egg  and  the  number  and  condition  of  the  spiders.  We 
found  that  the  egg  was  always  placed  either  on  the  side 
or  the  back  of  the  anterior  part  of  the  abdomen.  The 
number  of  spiders  stored  was,  as  we  have  already  stated, 
from  seven  to  fourteen.  A  fact  that  interested  us  greatly 
was  the  remarkable  accuracy  shown  by  the  wasp  in 
never  selecting  too  large  a  spider  for  the  calibre  of  the 
straw.  Oftentimes  it  was  an  extremely  close  fit,  but  it 
could  always  be  squeezed  down.  When  they  nested  in 
posts  they  used  at  times  much  larger  prey.  Unfortu- 
nately we  never  saw  this  species  capture  its  prey,  nor 
could  we  prevail  upon  it  to  sting  in  captivity,  but  the 
184 


THE   WOOD-BORERS 

number  of  spiders  that  we  found  in  straws  was  so  large 
as  to  afford  abundant  evidence  concerning  the  degree 
of  surgical  skill  possessed  by  the  wasps.  P.  marginatus 
and  P.  scelestus,  in  overpowering  their  large  fierce 
Lycosids,  must  sting  when  and  where  they  can,  but 
most  of  the  spiders  taken  by  rubrocinctum  are  inoffen- 
sive creatures,  and  there  is  so  little  need  to  be  careful 


TRYPOXYLON    RUBROCINCTUM 


or  adroit  in  dealing  with  them  that  she  has  time  and 
opportunity  to  sting  the  exact  spot  that  will  give  the 
best  results. 

The  concentration  of  the  nervous  system  in  the  Arach- 
nida  would  seem  to  conduce  very  strongly  to  uniform  re- 
sults from  the  stinging  of  the  wasps.    Unlike  the  larva 
185 


WASPS,    SOCIAL   AND    SOLITARY 

used  by  Ammophila,  with  its  chain  of  ganglia,  in  the 
Araneidae  the  whole  central  nervous  system,  including 
the  brain  and  the  ventral  cord,  forms  a  single  mass, 
pierced  by  the  oesophagus.  The  greater  part  of  this  mass, 
which  lies  behind  the  oesophagus,  represents  the  fused 
ventral  cord  from  which  the  nerves  radiate.  It  is  evident 
that  a  thrust  given  in  almost  any  part  of  the  ventral  face 
of  the  cephalothorax,  or  even  on  either  side  of  the  an- 
terior half  of  its  edges,  would  reach  the  nervous  centre. 
With  these  facts  before  us  let  us  turn  to  the  notes  made 
upon  the  condition  of  the  spiders  that  had  been  stung 
and  stored  up  in  the  nests  of  the  straw-stack.  By  the 
"first  cell"  we  mean  the  last  one  stored,  which  was 
naturally  the  first  one  opened. 

July  1 1.  Opened  a  nest  of  rubrocinctum.  The  first  cell 
contained  fourteen  live  spiders  with  a  newly  laid  egg. 
Some  of  the  spiders  were  very  lively,  moving  spontaneously. 
Second  cell,  ten  spiders,  one  dead,  others  alive,  and  an 
egg.  Third  cell,  eight  spiders,  three  dead  and  five  alive, 
and  the  egg. 

July  12.  In  each  of  the  first  and  second  cells  one  spider 
has  died  since  yesterday,  while  in  the  third  there  is  no 
change  in  their  condition.  The  egg  in  the  third  cell  hatched 
at  nine  in  the  morning,  and  the  one  in  the  second  cell  at 
three  in  the  afternoon. 

July  13.  In  the  first  cell  all  the  spiders  are  dead  but  one, 
186 


THE   WOOD-BORERS 

and  in  the  second,  all  but  four,  while  in  the  third  none  are 
alive. 

July  15.  All  the  spiders  in  the  second  cell  are  dead. 

July  1 6.  The  one  spider  in  the  first  cell  has  outlived  all 
the  others,  but  that,  too,  died  to-day. 

The  record  of  another  set  of  nests  is  as  follows:  On 
July  eighth  we  took  a  straw  with  a  wasp  as  she  went 
in  with  her  spider.  The  cell  was  not  sealed  up.  It 
contained  fourteen  specimens  of  three  species  of  orb- 
weavers,  and  the  egg  was  apparently  just  laid.  The 
spiders  were  pushed  in  very  tightly,  and  the  legs  and 
abdomens  were,  in  many  cases,  bent  to  one  side.  All 
were  limp,  but  alive.  By  July  tenth,  four  were  dead ; 
on  July  eleventh  the  egg  hatched.  By  July  thirteenth 
all  of  the  spiders  were  dead. 

It  is  unnecessary  to  give  the  history  of  other  nests  in 
detail,  since  these  facts  make  it  clear  that  there  is  a  great 
variation  in  the  degree  of  severity  with  which  the  spiders 
are  stung,  so  that  while  with  some  the  paralysis  is  com- 
plete, with  others  it  is  only  partial.  Some  were  killed 
outright,  others  lived  two  or  three  days,  while  still  others 
survived  for  two  weeks.  Compared  with  the  work  of 
the  Pelopaei  it  would  seem  that  a  smaller  number  of  the 
spiders  are  killed  at  once,  while  a  larger  number  die 
after  the  lapse  of  a  few  days.  None  of  the  victims  of 
187 


WASPS,    SOCIAL   AND    SOLITARY 

Trypoxylon  live  so  long  as  the  most  perfectly  paralyzed 
spiders  of  the  mud-daubers.  Two  of  them  lived  ten  and 
fifteen  days  respectively,  while  with  Pelopaeus  one  sur- 
vived until  the  thirty-eighth  and  one  until  the  fortieth 
day. 

The  egg  requires  from  forty  to  sixty  hours  for  its  de- 
velopment, and  the  larva  feeds  for  seven  or  eight  days 
before  spinning  its  cocoon.  Those  that  we  watched 
usually  disposed  first  of  the  abdomen  and  then  of  the 
cephalo thorax;  sometimes  they  would  consume  several 
abdomens  before  attacking  the  other  parts.  After  the 
body  was  devoured  the  legs  were  picked  up  and  eaten. 
When  the  supply  of  food  was  generous,  portions  of  the 
spiders  were  sometimes  left  untouched.  The  cocoons 
resembled  in  general  appearance  and  structure  those 
of  Pelopaeus. 

When  a  female  returns  with  her  load  she  usually 
hunts  about  for  a  few  moments  before  finding  her  nest, 
sometimes  entering,  first,  two  or  three  that  are  empty 
or  are  occupied  by  other  wasps ;  but  we  do  not  wish  to 
cast  any  reflection  upon  the  sense  of  locality  of  a  crea- 
ture that  is  able  to  find  one  particular  straw  out  of  the 
many  thousands  in  an  expanse  of  stack  twenty  feet 
high  by  twelve  wide.  We  ourselves  can  testify,  from 
experience,  to  the  extreme  difficulty  of  the  task. 
188 


THE   WOOD-BORERS 

After  the  storing  process  is  completed  the  female 
seals  up  the  nest  with  mud.  In  the  case  of  one  rubro- 
cinctum  that  we  were  watching,  she  began  to  close  the 
opening  at  four  in  the  afternoon  and  finished  her  work 
just  thirty  minutes  later.  In  this  time  she  made  ten 
journeys  for  mud,  bringing  it  in  pellets  in  her  mandibles. 
In  another  case,  also  a  rubrocinctum,  the  female,  after 
bringing  so  many  spiders  that  the  cell  was  full  up  to  the 
very  door  (which  we  saw  in  no  other  case),  went  away 
without  closing  it,  and  never  returned.  The  male  seemed 
uneasy  at  her  conduct,  and  several  times  flew  away, 
staying  an  hour  or  two  and  then  returning ;  but  after  a 
time  he  too  deserted  the  nest.  Whether  some  evil  fate 
overtook  the  female  or  whether  there  was  some  failure 
of  instinct  on  her  part,  can  only  be  conjectured ;  but  the 
latter  hypothesis  is  not  untenable,  since  out  of  seventy- 
six  nests  that  we  had  under  observation  seven  were 
cleaned  out  and  prepared  and  were  then  sealed  up 
empty.  We  have  often  found  similar  cases  among  the 
nests  of  the  blue  mud-dauber  wasps,  where  it  is  not  a 
very  uncommon  thing  for  the  absent-minded  females  to 
build  their  pretty  little  cylindrical  nests  with  infinite 
care  and  patience,  and  then  to  seal  them  up  without  put- 
ting anything  inside. 

Cocoons  of  rubrocinctum  that  were  gathered  in  the 


WASPS,    SOCIAL   AND    SOLITARY 

month  of  August  remained  over  the  winter  and  hatched 
in  May  and  June. 

Almost  as  interesting  as  rubrocinctum  is  the  slightly 
larger  species,  T.  albopilosum.  This  wasp  has  a  great 
liking  for  the  posts  that  support  the  balcony  of  our  cot- 
tage, a  preference  that  is  very  convenient  for  us,  as  it 
enables  us  to  sit  in  the  shade  and  watch  their  doings  at 
our  ease. 

One  afternoon  as  we  sat,  literally,  at  our  posts,  a  fe- 
male of  albopilosum  came  humming  along,  looking  very 
important  and  energetic,  as  though  she  had  planned 
beforehand  exactly  what  to  do.  She  entered  an  empty 
hole,  head  first,  and  at  once  began  to  gnaw  at  the  wood, 
kicking  it  out  backwards  with  considerable  violence. 
After  a  few  minutes  she  changed  her  method  of  work, 
and  began  to  carry  out  loads  of  wood  dust  in  her  mandi- 
bles, dropping  it  in  little  showers  just  outside  the  nest, 
and  then  hastening  back.  In  forty  minutes  she  carried 
out,  in  this  way,  upwards  of  fifty  loads.  She  then  flew 
away,  but  returned  in  ten  minutes  with  a  male.  She 
alighted,  he  took  his  place  on  her  back,  and  they  went  in 
together. 

After  a  time  they  came  out  and  both  flew  away,  but  the 
next  morning  they  came  back  and  the  nest  was  stored. 

In  this  species  the  male  does  not  always  come  out  of 
190 


MALE   TRYPOXYLON 


THE   WOOD-BORERS 

the  nest  when  the  female  brings  a  spider,  the  nest  being 
enough  larger  than  in  rubrocinctum  to  accommodate 
them  both  comfortably.  As  a  usual  thing,  however,  he 
enters  on  the  back  of  the  female.  The  spiders  brought 
by  albopilosum  are  larger  than  those  used  by  rubrocinc- 
tum. They  sometimes  bring  such  heavy  specimens  of 
Epeira  insularis  that  they  are  carried  with  difficulty, 
the  wasp  alighting  and  dragging  the  spider  into  the 
hole  instead  of  flying  directly  in  as  usual. 

We  watched  a  number  of  albopilosum  nests  during 
the  second  summer,  finding  them  in  several  instances 
through  the  loud  humming  of  the  female  while  she  was 
pushing  the  spiders  into  her  hole.  From  our  not  very 
extensive  study  of  the  spiders  taken  by  this  species  we 
are  of  the  opinion  that  some  are  killed  at  the  moment 
of  capture,  while  others  that  are  only  paralyzed  die  in 
the  nest  from  day  to  day. 

Mr.  W.  H.  Ashmead  has  noted  that  albopilosum 
stores  its  nest  with  aphides,  but  in  the  cases  that  we 
observed  they  used  only  spiders.  There  can  be  no  mis- 
take on  this  point,  as  we  more  than  once  took  the  spider 
from  the  wasp  as  she  was  entering  the  nest.  In  a  recent 
letter  Mr.  Ashmead  says  that  his  notes  were  made  in  the 
field,  and  that  he  probably  mistook  some  closely  allied 
species  for  this  one. 

193 


WASPS,    SOCIAL   AND    SOLITARY 

We  are  not  as  familiar  with  the  habits  of  T.  bidenta- 
tum  as  with  those  of  the  other  two,  but  we  have  a  few 
notes  relating  to  the  female.  This  little  worker  is  the 
smallest  of  the  three,  and  like  her  sisters  is  a  confirmed 
spider-hunter.  Once,  when  out  among  the  raspberry 
bushes,  we  had  the  good  fortune  to  witness  a  capture. 
The  wasp  seized  the  spider,  as  it  rested  on  a  leaf,  by  the 
top  of  the  cephalothorax,  and,  holding  it  firmly,  curved 
her  abdomen  under  and  stabbed  the  ventral  face  of  the 
cephalothorax.  All  her  motions  were  deliberate,  and 
after  the  operation  she  delayed  a  moment  before  picking 
it  up  by  a  leg  and  flying  off.  We  often  found  raspberry 
stems  which  had  been  filled  with  spiders  by  this  wasp, 
but  we  do  not  know  the  length  of  time  required  for  the 
development  of  the  egg,  nor  how  long  the  larva  eats  be- 
fore pupation.  The  cocoon  is  very  different  in  appear- 
ance from  those  of  rubrocinctum  and  albopilosum,  be- 
ing exceedingly  long,  slender,  and  almost  white,  instead 
of  short,  wide,  and  brown.  The  perfect  insects  come 
out  in  September,  and  the  last  cocoon  formed  is  the  first 
one  to  hatch.  This  was  also  true  of  the  cocoons  of 
rubrocinctum  formed  in  straws. 

Years  ago,  when  we  found  that  many  of  the  orb- 
weavers  laid  enormous  numbers  of  eggs  (A.  cophinaria 
from  500  to  2000),  we  wondered  what  became  of  the 
194 


THE   WOOD-BORERS 

thousands  of  spiderlings.  An  acquaintance  with  Trypo- 
xylon  has  shown  us  their  fate,  and  has  given  us  an  illus- 
tration of  how  closely  the  two  groups  are  related.  To 
make  a  very  modest  estimate  there  must  have  been  twenty 
wasps  at  work  in  our  straw-stack.  During  the  six  weeks 
which  make  the  busiest  part  of  their  working  season 
each  of  these  must  have  stored,  at  the  very  least,  thirty 
cells,  putting  an  average  of  ten  spiders  into  a  cell.  It  may 
then  be  considered  certain  that  the  straw-stack,  with  its 
working  surface  of  twelve  by  twenty  feet,  was  the  mauso- 
leum of  six  thousand  spiders,  and  it  is  very  probable  that 
twice  as  many  were  interred  within  its  depths.  It  must 
be  remembered,  too,  that  before  the  spiders  have  grown 
large  enough  to  be  interesting  to  rubrocinctum,  biden- 
tatum  has  had  her  turn  at  them,  and  that  those  that  are 
allowed  to  grow  too  large  for  rubrocinctum  are  preyed 
upon  grade  after  grade,  first  by  albopilosum  and  finally 
by  Pelopaeus,  Pompilus,  and  other  genera. 

The  wasps  of  this  genus  lose  their  interest  in  family 
affairs  about  the  second  week  in  August,  though  after 
this  time  they  may  still  be  seen  taking  their  well-earned 
holiday  on  the  blossoms  of  the  aster  and  the  golden-rod. 


Chapter    IX 

THE    SPIDER-HUNTERS 

T  T  THILE  Ammophila  provides  caterpillars  for  her 
T  T  larva,  and  Bembex,  after  the  manner  of  the 
social  wasps,  feeds  her  young  from  day  to  day  on  dead 
flies,  the  Pompilidae,  so  far  as  their  habits  are  known, 
all  prey  upon  spiders.  The  family  is  a  large  one  in  the 
United  States,  one  hundred  and  twenty-seven  species 
having  been  described.  The  members  of  the  group  differ 
in  size,  color,  and  habits,  and  the  individuals  of  the  same 
species  show  the  very  considerable  amount  of  variation 
which  seems  common  to  all  those  groups  of  animals 
which  have  been  carefully  studied.  Happily  the  old 
notion  that  habits  and  instincts,  unlike  structural  pe- 
culiarities, are  always  uniform,  is  no  longer  insisted 
upon,  and  there  is  ample  evidence  for  the  opinion  that 
functional  variations  are  as  common  as  morphological. 
We  have  studied  five  species  of  this  family,  and  have 
found  their  respective  r61es  of  great  interest. 
According  to  Fabre,  the  French  members  of  this 
196 


THE    SPIDER-HUNTERS 

genus,  although  they  do  not  make  their  own  nests,  still 
exercise  some  foresight  in  the  matter  by  selecting  a 
suitable  crevice  before  catching  their  prey.  Among  the 
species  that  we  have  studied,  quinquenotatus,  biguttatus, 


TORNADO    WASP   (POMPILUS   QUINQUENOTATUS)    DIGGING    NEST 

fuscipennis,  marginatus,  and  interruptus  first  catch  the 
spider  and  then  make  the  nest;    while  calipterus  and 
scelestus  prepare  the  nest  before  capturing  their  prey. 
Quinquenotatus  is  usually  rather  less  than  half  an 
inch  in  length  and  is  black,  the  abdomen  having  a 
variable  number  of  white  bands  and  a  white  tip. 
197 


WASPS,    SOLITARY   AND    SOCIAL 

*• 

It  was  on  the  last  day  of  July  that,  as  we  were  walking 

through  the  bean  field,  we  saw  a  cloud  of  fine  dust  which 
came  spurting  up  out  of  the  ground  like  water  in  a  foun- 
tain. By  watching  intently  we  saw  that  the  cause  of  the 
commotion  was  the  rapid  action  of  the  legs  of  some 
little  creature  that  was  almost  hidden  in  the  earth,  and 
this  proved  to  be  our  first  example  of  P.  quinqueno- 
tatus. 

She  was  working  away  as  furiously  as  though  she  had 
studied  the  poets  and  knew  her  carpe  diem  by  heart. 
Faster  and  faster  went  the  slender  little  legs;  higher 
and  higher  rose  the  jet  of  dust  above  her.  Then  sud- 
denly there  was  a  pause.  The  burrower  had  met  with 
some  obstacle.  A  moment  more  and  she  came  backing 
out  of  the  hole,  her  feet  slipping  on  its  crumbling  edges. 
In  her  mandibles  she  carried  a  pebble,  which  was  taken 
to  a  distance  of  four  or  five  inches.  Then,  moving 
quickly,  she  swept  away  the  dust  that  had  accumulated 
near  the  mouth  of  the  nest,  reentered  the  hole,  and  re- 
sumed the  labor  of  excavation. 

We  thought  that  the  rate  at  which  she  worked  was 
too  violent  to  be  kept  up  very  long;  and  sure  enough, 
before  ten  minutes  had  passed  the  nest  was  deep  enough 
for  her  purposes,  and  we  afterward  learned,  to  our  cha- 
grin, that  it  was  too  deep  for  ours.  The  wasp  came  out, 
198 


THE    SPIDER-HUNTERS 

circled  round  the  spot  three  or  four  times,  and  then  flew 
off  like  a  hurricane.  Never  have  we  seen  a  creature  so 
fiery,  tempestuous,  cyclonic.  Before  we  knew  her  proper 
title  we  took  to  calling  her 
the  tornado  wasp,  and  by 
that  name  we  shall  always 
think  of  her. 

Her  flight  was  too  rapid 
to  follow,  but  in  a  minute 
we  saw  her  returning.  She 
was  carrying  a  spider, (a 
good  -  sized  specimen  of 

_,  -.1-1111  POMPILUS    QUINQUENOTATUS 

Epeira  stnx,)wnicn  she  had 

evidently  deposited  somewhere  in  the  neighborhood 
before  beginning  to  dig.  Alighting  near  by,  she  left  the 
spider  lying  on  the  ground,  while  she  ran  to  her  nest  and 
kicked  out  a  little  more  earth.  Then  seizing  it  by  one 
leg,  she  dragged  it,  going  backward  herself,  into  the 
nest.  She  remained  hidden  for  about  two  minutes, 
then  reappeared,  and,  seeming  to  be  in  as  great  a 
hurry  as  ever,  filled  the  hole  with  dirt.  To  disguise 
the  spot  and  render  it  indistinguishable  from  the  rest 
of  the  field  was  her  next  care.  Hither  and  thither  she 
rushed,  now  bringing  little  pellets  of  earth  and  placing 
them  above  the  nest,  now  sweeping  away  the  loose  dust 
199 


WASPS,    SOCIAL   AND    SOLITARY 

which  might  suggest  the  presence  of  the  cache,  and 
now  tugging  frantically  at  a  stone  which  she  wanted  to 
place  over  the  hidden  treasure,  but  which  was  too  deeply 
embedded  in  the  earth  to  yield  to  her  efforts.  She  did 
her  work  faithfully,  although  with  such  eager  haste  that 
all  was  completed  at  the  end  of  twenty  minutes  from 
the  time  we  saw  her  first.  So  well  was  the  place  hidden 
that  it  was  only  by  careful  orientation  that  we  could  be 
certain  of  its  exact  locality. 

Her  task  accomplished,  away  flew  our  little  tornado 
as  though  she  were  pursued  by  the  avenging  spirits  of 
all  the  spiders  that  she  had  murdered,  although  more 
probably  she  was  off  in  quest  of  another  of  those  meek 
and  helpless  victims. 

"Now,"  we  said,  "we  will  trace  out  the  nest  and 
make  a  drawing  of  it.  We  will  take  the  spider  home  and 
note  its  condition  from  day  to  day,  watching  at  the 
same  time  the  development  of  the  larva." 

Enjoying  this  little  air-castle,  we  began  to  excavate. 
Having  had  experience  with  the  nests  of  Ammophila 
and  Diodontus,  and  knowing  that  the  task  might  not 
be  so  easy  as  it  looked,  we  went  to  work  with  all  possible 
care.  It  seemed,  however,  that  some  magician's  trick 
—  some  deception  of  the  senses  —  had  been  played 
upon  us.  We  saw  the  spider  interred ;  we  at  once  dug 
200 


THE    SPIDER-HUNTERS 

up  the  place  and  found  nothing.  Slowly  and  carefully 
we  enlarged  our  circle.  We  went  down  deeper  until 
the  opening  was  large  enough  to  hold  a  thousand  spiders, 
—  still  nothing.  Then  we  tried  another  plan.  Gathering 
all  the  earth  that  we  had  taken  out,  we  sifted  it  through 
our  hands  —  in  vain.  At  last  we  acknowledged  our- 
selves beaten,  and  trudged  home  empty-handed. 

Our  pride  was  destined  to  be  still  further  humbled. 
Three  times  within  that  same  week  we  saw  the  tornado 
wasp  bury  her  spider,  and  three  times  we  failed,  just  as 
incredibly,  to  find  it.  On  the  last  of  these  occasions  we 
did  not  let  her  fill  the  nest,  attempting  to  follow  the 
tunnel  and  get  out  the  spider  as  soon  as  the  egg  was 
laid,  but  the  loose,  unstable  character  of  the  soil  de- 
feated us. 

Our  fifth  example,  however,  dug  her  nest,  not  among 
the  beans  but  lower  down  in  the  potato  field,  where  the 
ground  was  firmer;  and  here  we  made  our  first  success- 
ful excavation,  —  successful  only  up  to  a  certain  point, 
since  in  getting  out  the  spider  we  dislodged  the  egg, 
and  although  it  was  at  once  replaced  it  never  developed. 
The  spider  was  placed  three  inches  below  the  surface, 
but  we  could  not  trace  the  tunnel.  At  our  next  oppor- 
tunity, wishing  to  make  good  this  failure,  we  placed  a 
blade  of  grass  in  the  opening  just  after  the  wasp  began 
201 


WASPS,    SOCIAL    AND    SOLITARY 

to  fill  it.  On  being  disturbed  she  assumed  the  most 
comically  threatening  aspect,  whirling  around,  lifting  her 
wings,  and  then  circling  about  us.  As  soon  as  we  moved 
back  she  dashed  at  the  grass-blade  and  pulled  it  out 
with  great  energy.  A  few  minutes  later  we  made  a  similar 
attempt,  and  again  she  frustrated  our  plan ;  but  when  we 
inserted  the  grass-blade  for  the  third  time,  the  nest  being 
now  half  filled,  she  let  it  remain.  Some  hours  later, 
with  this  to  guide  us,  we  succeeded  in  tracing  the  nest, 
but  much  to  our  disappointment  found  it  transformed 
into  a  banqueting  hall.  Scores  of  tiny  red  ants  had  dis- 
covered this  rich  store  of  food.  They  had  eaten  the  egg 
and  were  rapidly  finishing  the  spider. 

Twice  afterward,  in  opening  these  nests,  we  found 
the  same  ants  in  possession  before  us.  It  is  probable 
that  they  are  a  formidable  enemy  to  this  and  other 
species  of  Pompilus  ;  but  they  seem  to  find  the  spider 
by  burrowing  beneath  the  surface,  so  that  the  elaborate 
hiding  of  the  nest  from  above  cannot  be  meant  as  a  pro- 
tection from  them. 

Pompilus  quinquenotatus  has  a  decided  preference  as 
to  the  spider  that  she  takes.  While  Pelopaeus  and  Try- 
poxylon  are  entirely  indifferent  both  as  to  size  and 
species,  and  the  more  nearly  related  Pompilus  margi- 
natus  takes  Thomisus,  Drassus,  Attus,  Agalena  or 
202 


THE    SPIDER-HUNTERS 

Lycosa,  this  more  fastidious  wasp  will  not  be  tempted 
from  the  spider  of  her  choice.  In  more  than  fifty  ex- 
amples the  victim  in  the  play  was  invariably  Epeira 
strix.  If  she  must  confine  herself  to  one  species  she  has 
made  a  fortunate  selection,  since  there  is  no  other  spider 
so  common  in  our  neighborhood,  not  only  in  the  woods, 


EXAMPLE  OF  EPEIRA  STRIX  THAT  HAS  BEEN 
PARALYZED  AND  HUNG  UP  ON  BEAN  PLANT 
BY  POMPILUS  QUINQUENOTATUS,  THAT  IT 
MAY  BE  OUT  OF  THE  WAY  OF  ANTS  WHILE 
SHE  DIGS  HER  NEST 

but  around  the  barns  and  outbuildings.  Most  frequently 
it  was  the  female  that  was  taken,  but  this  does  not  im- 
ply a  preference  for  that  sex,  since  the  females  are  more 
203 


WASPS,    SOCIAL   AND    SOLITARY 

abundant  than  the  males.  \  We  have  never  seen  the 
spider  captured  and  do  not  know  where  the  sting  is 
given,  but  certainly  this  wasp  wounds  her  prey  very 
severely.  The  spiders  that  we  took  from  her  were  either 
dead,  or  so  completely  paralyzed  that  it  required  great 
care  and  the  use  of  a  magnifying  glass  to  determine 
that  they  were  alive. 

The  next  stage  of  her  proceedings  we  are  familiar 
with,  as  we  have  frequently  seen  the  wasp  carry  the 
spider.  (Unlike  her  sister,  marginatus,\she  usually  flies 
with  it,  and  seems  not  at  all  encumbered  by  its  weight. 
In  many  cases,  however,  she  drags  it,  holding  it  by  one 
leg  and  running  rapidly  backward. 

A  suitable  place  for-  the  nest  being  found,  the  spider 
is  very  prettily  taken  care  of  while  the  work  is  in  pro- 
gress. A  plant,  usually  a  bean  or  a  sorrel,  is  chosen,  and 
the  strix  is  hung  in  the  crotch  of  a  branching  stem,  where 
it  will  be  safe  from  the  depredations  of  ants.  This  pre- 
caution is  not  always  taken.  We  have  many  times  seen 
the  spider  left  on  the  ground,  although  there  were  plenty 
of  plants  at  hand. 

The  next  point  is  to  decide  upon  the  precise  spot 
for  the  nest,  and  here  our  wasp  shows  herself  very  un- 
certain and  hard  to  please.  Never  have  we  seen  one 
settle  down  and  complete  her  work  in  the  spot  first 
204 


THE    SPIDER-HUNTERS 

chosen.  She  dashes  at  a  place  and  scratches  and  digs 
away  with  furious  energy  for  a  few  minutes,  and  then, 
starting  up,  she  darts  wildly  hither  and  thither  until  a 
new  place,  near  by,  is  fixed  upon  and  another  beginning 
made.  In  one  instance  eight  nests  were  started  and 
some  of  them  nearly  finished,  the  little  worker  seeming 
to  be  beside  herself  with  excitement.  After  the  decision 
is  finally  made  the  tunneling  is  a  rapid  process.  In  one 
case  it  took  the  wasp  a  whole  hour  to  complete  the  work, 
but  out  of  the  thirty  nests  that  we  saw  made,  nineteen 
were  finished  in  from  twenty  to  twenty-five  minutes. 
Like  -Fables-  Sphex  the  wasp  interrupts  herself  three 
or  four  times  to  visit  her  spider  and  make  sure  that  it  is 
safe.  When  all  is  done  she  brings  the  strix  to  within 
a  foot  or  two  of  the  opening,  runs  to  the  nest  to  take  a 
final  look,  and  then,  going  backward  herself,  pulls  it 
inside. 

In  two  instances  we  saw  the  fidgety  little  creature 
go  through  a  most  comical  performance,^which  again 
recalls  the  Sphex  of  Fabre.\  Leaving  her  treasure  on 
the  ground,  she  ran  to  the  nest  and  kicked  out  a  little 
more  earth;  hastening  back  she  dragged  it  an  inch 
nearer  ;  then  away  she  went  to  the  nest  again  for  more 
digging,  and  so  on,  dropping  her  spider  half  a  dozen 
times  before  she  at  last  brought  it  home.  In  two  other 
205 


WASPS,    SOCIAL   AND    SOLITARY 

cases  in  which  there  was  no  such  anxiety  about  the 
size  of  the  nest,  there  was,  in  icality,  more  reason  for  it. 
Indeed,  in  one  instance  the  opening  had  to  be  enlarged 
before  the  spider  could  be  taken  in.  There  is  a  wide- 
winged  parasitic  fly  that,  having  nothing  else  to  do,  lays 
prodigious  numbers  of  eggs,  not  in  any  particular  nest, 
but  at  the  edge  of  holes  wherever  it  may  chance  to  see 
them.  It  hovers  about  over  the  ground  until  it  comes 
to  an  opening,  dips  down  twice  or  thrice,  ovipositing 
each  time,  and  then  passes  along.  The  habit  of  scratch- 
ing out  a  little  dirt  at  the  threshold,  just  before  the  prey 
is  brought  in,  seemingly  from  a  desire  to  enlarge  the 
nest,  or  in  other  cases  from  mere  nervousness,  is  per- 
haps of  use  in  destroying  these  eggs,  which  might  other- 
wise adhere  to  the  spider  or  caterpillar  as  it  is  dragged 
over  them. 

The  laying  of  the  egg  takes  only  two  or  three  minutes, 
and  then  the  hole  is  filled  up.  In  this  part  of  her  work 
quinquenotatus  shows  a  great  deal  of  variation,  some- 
tunes  coming  out  of  the  hole  and  sweeping  in  the  dirt 
with  her  first  legs  and  sometimes  standing  in  the  tunnel 
while  she  draws  the  earth  in  with  her  mandibles  and 
then  jams  it  down  with  the  end  of  her  abdomen.  The 
former  plan  was  in  vogue  in  the  garden,  while  the  latter 
was  more  common  with  the  wasps  on  the  island.  After 
206 


THE    SPIDER-HUNTERS 

the  hole  is  filled  the  spotjs  covered  with  pellets  of  earth 
and  pebbles  brought  frur.ii  a  little  distance,  very  much 
as  is  done  by  Ammophila. 

When  we  found  that  quinquenotatus  was  a  very  com- 
mon species,  and  that  nearly  every  day  brought  us  a 
fresh  example,  we  thought  that  we  had  the  question 
of  its  stinging  habits  in  our  own  hands.  What  could 
be  easier  than  to  carry  a  strix  about  with  us  and  to  ex- 
change it,  when  opportunity  offered,  for  the  paralyzed 
spider  of  the  wasp?  The  good  results  obtained  by 
Fabre  and  Marchal  from  this  manceuvre  made  us  con- 
fident of  success.  We  did  not  doubt  that  when  the  wasp 
came  for  her  spider  and  found  it  livelier  than  it  ought 
to  be,  she  would  repeat  the  stinging  operation  before 
our  eyes. 

Accordingly,  the  next  time  that  we  saw  quinquenota- 
tus digging  we  made  a  diligent  search  for  her  spider, 
and  soon  found  it  on  a  bean  plant  five  feet  away.  Just 
as  we  discovered  it,  however,  the  wasp  swooped  down 
and  carried  it  to  some  purslain,  close  to  the  hole,  where 
she  hung  it  up  again,  while  she  went  to  make  her  final 
preparations  at  the  nest.  We  seized  our  chance,  and 
quickly  substituted  a  fresh  strix  for  the  one  that  had 
been  paralyzed.  According  to  the  habit  of  its  species 
when  danger  threatens,  it  kept  perfectly  quiet,  and  when 
207 


WASPS,    SOCIAL   AND    SOLITARY 

the  wasp  returned  it  was  hanging  there  as  motionless 
as  a  piece  of  dead  matter.  How  she  knew  the  difference 
was  a  mystery,  but  she  would  not  touch  it.  She  seemed 
to  think  that  she  had  made  a  mistake  in  the  locality 
and  that  her  own  spider  must  be  hanging  somewhere 
close  by,  for  she  hunted  all  over  that  plant  and  then 
over  several  others  near  to  it,  returning  continually  to 
look  again  in  the  right  spot.  After  five  minutes  she  gave 
it  up,  circled  about  three  or  four  times,  and  flew  off  in 
the  direction  of  the  woods  to  catch  another  spider. 

Why  did  she  go  to  the  woods?  When  she  realized 
that  the  strix  she  had  stung  was  gone  and  that  she  must 
have  another,  why  did  she  not  take  the  one  that  hung 
there  in  plain  view?  Our  failure  could  not  have  been 
due  to  the  fact  that  we  had  handled  the  spider,  since, 
when  on  other  occasions  we  took  one  that  had  been 
paralyzed,  examined  it  and  then  returned  it  to  the  wasp, 
she  accepted  it  without  hesitation. 

Disappointed  though  we  were  at  the  irrational  con- 
duct of  our  wasp,  we  resolved  to  await  her  return  and 
to  try  again.  In  forty  minutes  she  came  back  with  an- 
other spider,  but  instead  of  taking  it  into  the  nest  she 
hung  it  upon  a  bean  plant  near  by  and  then  proceeded 
to  dig  a  new  hole  a  few  inches  distant  from  the  first. 
Foolish  little  wasp,  what  a  waste  of  labor !  Truly,  if 
208 


THE    SPIDER-HUNTERS 

you  are  endowed  with  energy  beyond  your  fellows  you 
are  but  meagrely  furnished  with  reason. 

Again  we  availed  ourselves  of  our  opportunity,  and 
substituted  our  spider  for  hers.  This  time  it  had  grown 
weary  of  playing  its  motionless  role,  and  frequent  read- 
justments were  necessary  in  order  to  keep  it  in  position. 
At  the  moment  that  the  wasp  came  back  to  take  it,  the 
spider  scrambled  from  its  place  and  began  to  make  its 
way  along  the  stem.  The  wasp  evidently  saw  it,  for  she 
hovered  over  it  a  moment.  She  then  flew  to  the  next 
plant,  where  she  hunted  about  over  the  leaves  and 
branches  in  search  of  her  lost  treasure.  After  a  time 
she  returned.  The  spider  had  now  come  to  a  standstill, 
and  the  wasp  examined  it  attentively,  although  without 
touching  it.  She  then  flew  away  without  circling  at  all, 
which  might,  perhaps,  be  taken  as  an  indication  that 
she  had  no  intention  of  returning  to  a  place  where  she 
had  fared  so  badly. 

Just  at  this  moment  we  chanced  to  see  another  para- 
lyzed strix  hanging  near  by.  Again  the  exchange  of 
our  specimen  was  accomplished;  but  when  the  second 
wasp  came  to  find  her  spider  she  gave  us  no  more  satis- 
faction than  the  first.  The  substitute  hung  there  quietly 
enough.  We  ourselves  could  not  have  distinguished  it 
from  the  original,  but  quinquenotatus  took  a  good  look 
209 


WASPS,    SOCIAL    AND    SOLITARY 

at  it,  decided  that  something  was  wrong,  hunted  about 
a  little  for  her  own  spider,  and  then  flew  away. 

We  had  then,  as  the  fruit  of  our  morning's  work, 
gained  nothing  in  regard  to  a  knowledge  of  the  stinging 
habits  of  our  wasp,  but  at  least  we  had  secured  three 
freshly  paralyzed  spiders  to  add  to  our  laboratory  col- 
lection. As  to  the  strix  that  had  so  kindly  assisted  us 
in  our  experiments,  we  placed  it  on  a  bush  in  the  plea- 
santest  and  most  secluded  corner  of  the  garden  and  left 
it  there,  wishing  it  a  long  and  happy  life. 

Later  on  in  the  season  we  tried  the  same  experiment. 
Taking  her  spider  from  quinquenotatus  as  she  was 
dragging  it  to  her  nest,  we  offered  her  a  very  lively  strix 
in  its  place.  She  would  not  notice  it  at  all,  and  soon  flew 
away.  Half  an  hour  later  she  reappeared,  and  seemed 
to  be  looking  for  a  place  to  dig.  As  she  ran  about  on 
the  ground  we  offered  her  another  spider,  dropping  it 
on  the  ground  in  front  of  her.  This  one  behaved  ad- 
mirably, drawing  up  its  legs  and  keeping  perfectly  still, 
not  moving  even  when  she  felt  of  it  and  turned  it  over, 
but  it  was  left  without  any  display  of  interest  or  emotion. 

One  day  we  saw  a  quinquenotatus  finish  her  nest  and 

go  after  her  spider.    She  was  absent  for  some  time,  and 

when  an  ant  passed  by,  dragging  a  paralyzed  strix  that 

had  evidently  been  stolen  from  some  wasp,  we  thought 

210 


THE    SPIDER-HUNTERS 

that  the  one  we  were  watching  had  been  robbed,  and 
rescuing  the  spider,  placed  it  in  the  doorway  of  the 
nest.  We  had  judged  wrongly,  for  a  moment  later  our 
wasp  came  back  bringing  her  own  spider,  and  dropping 
it  near  by,  ran  to  look  at  her  nest.  She  was  disturbed 
at  finding  the  way  blocked,  and  dug  out  a  little  earth 
to  one  side  of  the  strix.  Then  she  flew  to  some  holes  in 
the  ground  not  far  away  and  dug  a  little,  first  in  one  and 
then  in  the  other.  After  this  she  took  a  look  at  her  spider, 
and  then  went  back  and  dug  a  little  more  at  her  own 
nest.  Finally  she  seized  the  impeding  strix  by  a  leg, 
dragged  it  out  of  the  way  and  paid  no  further  attention 
to  it,  storing  her  own  spider  and  departing,  although 
the  one  she  had  rejected  might  have  saved  a  hunting 
expedition. 

At  another  time  we  saw  two  wasps  digging  their  nests 
two  or  three  feet  apart.  One  of  them  finished  before  the 
other,  and  being  unable  to  find  her  own  spider  (probably 
it  had  been  carried  away  by  the  ants),  she  seized  that 
of  her  neighbor  and  bore  it  away.  The  rightful  owner 
saw  from  a  distance  what  was  happening,  and  ran  to 
the  rescue.  A  violent  scrimmage  ensued,  the  two  wasps 
clinching  and  rolling  over  and  over  together.  The  rob- 
ber escaped  and  made  off,  but  was  followed  and  caught 
again.  She  fought  so  well  for  her  ill-gotten  treasure, 


WASPS,    SOCIAL   AND    SOLITARY 

however,  that  she  finally  conquered  the  other  and  hur- 
ried off  with  her  prize.  She  showed  by  her  manner  that 
she  felt  the  need  of  haste,  for  instead  of  laying  the  spider 
down  and  looking  at  the  nest,  she  dragged  it  directly  in, 
as  though  she  feared  another  attack.  This  was  the  first 
time  that  we  had  ever  seen  these  wasps  fighting  over 
their  prey,  and  we  were  surprised  to  find  that  they  would 
take  spiders  which  they  had  not  captured  themselves, 
since  when  we  had  tried  to  exchange  with  them  they  had 
refused  to  carry  out  our  scheme.  This  was  clearly  an 
intelligent  act,  and  could  not  be  an  affair  of  instinct. 

Once  again  we  witnessed  a  similar  struggle.  One  of 
these  wasps  was  laboriously  dragging  her  strix  up  a 
steep  hillside,  when  a  much  bigger  one  of  the  same  spe- 
cies descended  upon  her  and  seized  the  spider.  She  was 
loath  to  give  it  up,  and  they  both  pulled  until  it  seemed 
as  though  the  poor  creature  would  be  dismembered. 
The  highway  robber  came  off  victorious,  and  after  flying 
to  a  distance  hung  the  spider  up  while  she  finished  a 
partly  made  nest,  and  then  stored  it  away.  It  may  be 
said  in  extenuation  of  her  conduct  that  since  she  had  a 
nest  started  she  had  probably  been  robbed  herself,  and 
therefore  felt  that  she  was  entitled  to  a  spider. 

The  nests  of  quinquenotatus  vary  considerably  ac- 
cording to  the  kind  of  soil  in  which  they  are  made,  the 


THE    SPIDER-HUNTERS 

firm  clay  of  the  garden  giving  a  result  quite  different 
from  the  fine  dry  earth  of  the  island,  in  which  they  are 
usually  much  larger,  and  scarcely  to  be  distinguished 
from  the  holes  of  Bembex  spinolae.  In  both  localities, 


NEST   OF    P.   QUINQUENOTATUS 

however,  the  nest  consisted  of  a  short  tunnel,  running 

obliquely  downward,  with  a  slight  enlargement  at  the 

end,  but  with  no  change  in  the  direction  of  the  gallery. 

In  the  loose  sand  of  a  steep  hillside  we  found  that  the 

wasps  had  a  different  method.    Their  tunnels  in  this 

place  filled  up  nearly  as  fast  as  they  could  dig  them, 

and  when  they  had  reached  a  depth  of  half  an  inch  they 

213 


WASPS,    SOCIAL   AND    SOLITARY 

turned  off  at  a  right  angle,  and  excavated  in  an  entirely 
new  direction.  They  probably  derived  some  advantage 
from  this  variation,  for  we  saw  four  in  succession  follow 
the  same  plan,  which  certainly  appeared  to  be  an  in- 
telligent adaptation  of  means  to  ends. 

We  once  saw  a  wasp  of  this  species  digging  her  nest 
on  the  Bembex  field.  When  finished  it  was  a  large  hole 
which  could  not  have  been  distinguished  from  those 
of  spinolae,  which  were  open  all  about,  the  weather 
being  bright  and  sunny.  She  flew  off,  and  soon  reap- 
peared with  her  spider,  which  was  dropped  three  feet 
away  while  she  ran  to  make  sure  that  all  was  right; 
and  now  followed  something  that  we  had  never  seen 
before  —  she  could  not  find  her  nest.  She  flew,  she  ran, 
she  scurried  here  and  there,  but  she  had  utterly  lost  track 
of  it.  She  approached  it  several  times,  but  there  are 
no  landmarks  on  the  Bembex  field.  We  have  often 
wondered  how  they  find  their  own  places.  After  five 
minutes  our  wasp  flew  back  to  look  at  her  spider,  and 
then  returned  to  her  search.  She  now  began  to  run  into 
the  Bembex  holes,  but  soon  came  out  again,  even  when 
not  chased  out  by  the  proprietor.  Suddenly  it  seemed 
to  strike  her  that  this  was  going  to  be  a  prolonged  affair, 
and  that  her  treasure  was  exposed  to  danger;  and  hurry- 
ing back  she  dragged  it  into  the  grass  at  the  edge  of  the 
214 


THE    SPIDER-HUNTERS 

field,  where  it  was  hidden.  Again  she  resumed  the  hunt, 
flying  wildly  now  all  over  the  field,  running  into  wrong 
holes  and  even  kicking  out  earth  as  though  she  thought 
of  appropriating  them,  but  soon  passing  on.  Once 
more  she  became  anxious  about  the  spider,  and  carry- 
ing it  up  on  to  a  plant  suspended  it  there.  Now  she 
seemed  determined  to  take  possession  of  every  hole 
that  she  went  into,  digging  quite  persistently  in  each, 
but  then  giving  it  up.  On  one  that  seemed  to  be  un- 
occupied she  labored  at  enlarging  the  entrance,  until  we 
thought  that  she  had  mistaken  it  for  her  own,  or  at 
least  had  determined  to  use  it.  At  last,  however,  she 
made  up  her  mind  that  all  further  search  was  hopeless 
and  that  she  must  start  afresh;  and  forty  minutes  from 
the  time  that  we  saw  her  first  she  began  a  new  nest  close 
to  the  spider,  as  though  she  would  run  no  more  risks. 
This  nest  was  successfully  completed,  and  the  spider 
was  stored  away  without  further  misadventure. 

The  egg  of  quinquenotatus  can  be  but  lightly  attached 
to  the  spider,  for  only  once,  out  of  many  attempts,  did  we 
succeed  in  getting  it  out  without  displacing  it.  In  this 
case  three  days  elapsed  before  it  hatched.  The  larva  ate 
for  a  day  or  two,  but  then  pined  away  and  died.  An- 
other nest  was  opened  on  the  tenth  day  after  the  egg 
was  laid,  and  in  this  the  spider  had  been  entirely  eaten 
215 


WASPS,    SOCIAL   AND    SOLITARY 

and  the  larva  was  just  spinning  its  cocoon;  so  that  the 
larval  stage  probably  occupies  about  a  week. 

A  summary  of  our  notes  shows  a  very  wide  variation 
in  the  condition  of  the  spiders  stored  by  this  wasp.  Out 
of  eleven  that  were  stung  three  were  killed  at  once,  two 
lived  four  days,  one  five,  one  eleven,  one  twenty-three, 
one  twenty-five,  one  thirty-one,  and  one  at  least  forty 
days  and  probably  longer. 

We  look  back  with  much  pleasure  upon  our  acquaint- 
ance with  this  gay,  excitable  little  wasp.  She  was  so  full 
of  breezy  energy  that  it  was  always  delightful  to  meet 
her,  and  she  showed  so  wide  a  variation  in  individual 
character  that  we  seldom  watched  her  without  learning 
something  new. 

Pompilus  fuscipennis,  a  little  smaller  than  P.  quinque- 
notatus,  is  black,  with  the  red  girdle  that  appears  so 
frequently  among  the  solitary  wasps.  The  first  time 
that  we  ever  saw  this  wasp  she  was  running  rapidly 
backward  over  the  bare  ground,  the  brilliant  red  of  her 
body  flashing  in  the  sunlight  as  she  dragged  along  a  little 
spider  of  the  genus  Thomisus.  Presently  she  carried  it 
up  on  to  a  leaf  and  began  to  bite  at  it,  but  being  dis- 
turbed by  an  ant,  hurried  on  with  a  much  agitated  man- 
ner. Soon  she  stopped  again  and  resumed  her  attack, 
biting  savagely  at  the  legs  near  their  junction  with  the 
216 


THE    SPIDER-HUNTERS 

body,  and  now,  looking  closely,  we  saw  that  two  of  them 
had  been  completely  cut  off.  While  occupied  in  this  way 
the  wasp  was  evidently  intensely  excited.  She  lay  on 
one  side  with  the  abdomen  bent  under,  turning  the 
spider  over  and  over  as  she  worked.  After  a  time  she 
carried  it  onward  to  the  potato-field,  where  the  plants 
afforded  some  shelter,  and  placing  it  upon  a  leaf,  well 
above  the  ground,  began  to  dig  near  by.  She  worked 
almost  entirely  with  her  mandibles,  lying  sometimes  on 
her  side  and  sometimes  on  her  back  as  she  cut  away 
the  earth,  which  was  pushed  out  with  the  end  of  her 
abdomen.  When  she  had  worked  for  ten  minutes  and 
had  gone  in  the  length  of  her  body,  she  picked  up  the 
spider  and  rapidly  made  off  with  it,  several  times  rising 
on  her  wings  and  flying  backward  for  a  few  inches.  A 
little  further  along  she  again  deposited  it  on  a  leaf  and 
began  to  dig  in  a  fresh  place.  At  the  end  of  twenty  min- 
utes the  nest  was  ready,  but  in  bringing  the  spider  she 
missed  her  direction  and  carried  it  to  one  side.  Drop- 
ping it  on  the  ground,  she  began  to  hunt  about  for  her 
hole,  but  was  distracted  with  excitement  and  ran  so 
far  afield  that  we  feared  she  would  never  find  it.  At 
last,  however,  she  came  to  the  place,  ran  in  for  a  mo- 
ment, brought  the  spider  nearer,  dropped  it  and  ran 
to  the  nest  once  more,  caught  it  up  again,  and  tried  to 
217 


WASPS,    SOCIAL   AND   SOLITARY 

back  in  with  it.  She  was  holding  it  by  the  under  side 
of  the  body,  the  venter  being  toward  the  hole,  and  the 
legs  spread  out  and  stopped  its  entrance.  A  moment's 
tugging  convinced  her  that  this  would  not  do,  and  she 
then  turned  the  spider  over,  holding  it  by  the  back, 
whereupon  the  legs  at  once  folded  themselves  across 
the  underside  of  the  thorax,  and  it  was  drawn  out  of 
sight. 

After  the  egg  was  laid  the  wasp  came  up  to  the  edge 
of  the  hole,  and  drawing  in  some  earth  with  her  mandi- 
bles began  to  dance  up  and  down  upon  it,  jamming  it 
into  place  with  her  abdomen.  Afterwards  she  came 
up  higher  and  drew  the  dirt  in  with  her  first  legs,  not 
getting  out  of  the  hole  until  it  was  entirely  filled  up. 
Then  began  a  remarkable  performance.  Bracing  herself 
firmly  on  her  legs  she  used  the  end  of  her  abdomen  as 
an  instrument,  and  with  it  she  now  pounded  the  earth, 
now  rubbed  it,  like  a  pestle  in  a  mortar,  and  now  used 
it  as  a  brush  to  sweep  away  loose  dust.  Sometimes  she 
would  throw  a  little  earth  back  under  her  body  with  her 
mandibles  and  rub  it  down  with  her  abdomen.  This 
part  of  the  work  being  finished,  she  spent  a  few  minutes 
in  sweeping  the  ground  with  her  first  legs,  and  then 
brought  a  quantity  of  small  objects  and  placed  them 
over  the  nest,  —  a  little  stick,  the  petal  of  a  faded  flower, 
218 


THE    SPIDER-HUNTERS 

a  scrap  of  dead  leaf,  and  so  on,  until  ten  or  twelve  things 
had  been  collected.  This  artistic  finishing  up  of  her 
duties  recalled  Ammophila;  but  among  our  subsequent 
examples  of  fuscipennis  we  never  saw  one  do  her  work 
with  such  nicety.  They  were  usually  contented  to  fill 
in  the  nest  more  or  less  compactly,  sometimes  doing 
much  of  the  work  from  the  outside,  to  brush  off  the 
surface  without  any  rubbing  or  pounding,  and  then  to 
bring  two  or  three  little  pebbles  or  lumps  of  earth 
to  place  over  the  spot. 

So  far  as  we  were  concerned  this  was  one  of  the  most 
fearless  of  the  wasps,  not  even  interrupting  her  work 
when  we  once  placed  a  glass  over  her  as  she  was  filling 
her  nest;  but  the  approach  of  an  ant  would  throw  her 
into  a  perfect  panic,  and  seizing  her  spider  she  would 
make  off  with  every  sign  of  terror.  It  is  difficult  to  under- 
stand why  wasps  of  this  species,  as  well  as  of  biguttatus, 
never  offer  combat  to  the  ants  that  rob  them  right  and 
left,  but  invariably  seek  safety  in  retreat.  Their  attitude 
toward  other  robbers  is  quite  different.  We  once  saw  a 
fuscipennis  that  was  dragging  a  Lycosid  attacked  by  a 
bigger  wasp  of  the  same  species.  Number  One  left  her 
spider  on  the  ground  and  chased  Number  Two  to  a  dis- 
tance; but  no  sooner  had  she  returned  and  taken  it  up 
than  Number  Two,  bold  and  unashamed,  was  at  her 
219 


WASPS,    SOCIAL   AND    SOLITARY 

heels  again,  and  the  scene  was  repeated.  The  object 
of  the  robber  was  to  seize  a  leg  of  the  spider,  and  when- 
ever she  succeeded  in  doing  this  she  jerked  it  free,  and 
made  off  with  it  very  rapidly ;  but  when  the  owner  pur- 
sued and  caught  up  with  her  she  relinquished  the  prize 
without  a  struggle.  Why  did  she?  She  was  the  bigger 
and  the  stronger,  and  possession  is  nine  points  of  the 
law  in  Waspland  as  elsewhere;  but  conscience  made  a 
coward  of  her,  while  the  other  was  strong  in  her  right- 
eous cause.  After  a  time  we  captured  the  little  pirate; 
but  now  the  nerves  of  the  rightful  owner  were  completely 
upset,  and  she  flew  away,  deserting  the  spider  for  which 
she  had  battled  so  bravely. 

The  most  interesting  thing  about  fuscipennis  is  her 
habit  of  biting  the  legs  of  her  victims.  The  instinct  is 
very  irregularly  developed,  since  four  out  of  ten  spiders 
had  not  lost  any  legs,  while  the  others  had  been  deprived 
of  one  or  two.  No  one  who  has  watched  the  wasp  can 
doubt  that  the  habit  is  related  to  the  fact  that  she  makes 
a  very  small  nest  in  comparison  to  the  size  of  her  prey. 
The  spider  never  went  in  easily,  always  requiring  to  be 
shifted  and  turned  and  tugged  at.  There  was  an  especial 
tendency  to  bite  at  the  legs  at  this  point  of  time,  when 
the  wasp,  standing  within  the  tunnel,  was  trying  to  drag 
the  spider  down.  In  one  instance  she  managed  to  get 


THE    SPIDER-HUNTERS 

it  past  the  entrance,  but  it  stuck  in  the  gallery ;  and  after 
working  at  it  in  that  position  for  a  time  she  brought  it 
out,  subjected  the  legs  to  a  severe  squeezing,  and  then 
tried  again.  It  was  still  a  very  bad  fit,  but  by  turning  it 
about  and  pulling  at  it  she  succeeded  in  getting  it  in.  It 
may  be  that  the  object  of  biting  the  legs  is  not  to  remove 
them,  but  to  render  them  limber  so  that  they  will  bend 
easily.  Whatever  the  process  may  be,  it  is  repeated  at 
intervals  from  the  time  the  spider  is  captured.  As  she 
carries  it,  the  wasp  pauses  again  and  again,  now  on 
bare  ground  and  now  in  a  sheltered  place  or  on  some 
plant,  to  renew  her  efforts  at  getting  the  legs  into  a  satis- 
factory state. 

P.  fuscipennis  rarely  circles  about  when  leaving  a 
place;  this  is  unfortunate,  since  her  sense  of  locality 
seems  to  be  particularly  weak.  She  nearly  always  has  to 
hunt  for  the  plant  upon  which  she  has  placed  her  spider, 
and  always  loses  track  of  her  nest  when  she  tries  to 
bring  the  spider  to  it.  We  once  caught  her  as  she  was 
carrying  her  spider,  and  then  released  her  on  the  same 
spot;  but  she  became  so  much  confused  that  without 
our  assistance  she  would  never  have  found  it  again. 

Our  acquaintance  with  Pompilus  marginatus  began 
in  the  middle  of  July.  She  is  a  small  creature,  only 
half  an  inch  long,  and  is  dressed  in  black,  with  a  bright 

221 


WASPS,    SOCIAL   AND    SOLITARY 

orange  spot  on  each  side  of  the  anterior  part  of  the  ab- 
domen. We  were  watching  the  pretty  little  Diodonti,  as 
they  filled  their  holes  with  aphides,  when  we  saw  her 
going  backward,  dragging  along  a  medium-sized  spider. 
Soon  she  came  to  an  onion  flower  that  was  lying  on  the 
ground.  Here  she  stopped  and,  after  a  moment's  hesi- 
tation, drew  her  prey  in  among  the  blossoms  of  the 
cluster  so  that  it  was  hidden  from  view.  It  was  not  long 
before  she  came  out  and  began  to  fly  about  near  the 
ground,  frequently  alighting  to  poke  her  head  into 
cracks  and  to  run  again  and  again  into  little  chance 
holes.  Never  did  an  insect  behave  in  a  more  demented 
manner,  and  although  there  may  have  been  a  method 
in  her  madness  it  was  difficult  to  discover  it.  No  hole 
nor  cranny  pleased  her,  and  back  she  flew  to  the  onion 
to  see  whether  her  booty  were  safe.  For  fifteen  minutes 
she  ran  and  flew  now  here,  now  there,  hurry,  and  anxiety 
in  every  movement,  returning  frequently  to  reassure 
herself  about  the  spider.  Several  times  she  entered  a 
hole  at  the  base  of  a  weed,  not  a  made  nest,  but  an  acci- 
dental crevice;  and  this  spot  was  at  length  chosen  either 
as  a  temporary  or  a  final  resting  place  for  her  spider, 
since  she  dragged  it  from  the  onion  and  deposited  it 
here.  We  tried  to  capture  the  wasp;  but  having  failed 
in  this,  we  dug  out  the  spider.  It  was  three  inches 


THE    SPIDER-HUNTERS 

down,  the  hole  being  deeper  than  it  looked  from  the 
outside.  There  was  no  egg  upon  it.  Evidently  the  work 
had  not  been  finished,  for  the  restless  creature  returned 
fifteen  times  within  an  hour  to  the  broken  nest,  either 
for  the  purpose  of  laying  her 
egg  or  to  remove  the  spider  to 
another   resting-place   on  her 
homeward  way. 

This  was  our  first  specimen 
of  marginatus,  and  a  month 
passed  before  we  met  another. 
It  was  while  watching  some 
Bembecid*  that  we  saw  the  POMPILUS  MARGINATUS 
pretty  little  orange-spotted  worker  dragging  a  small 
Thomisid  across  their  nesting-ground.  The  spider  was 
so  small  that  she  held  it  in  her  mandibles  well  above 
the  ground,  and  we  speak  of  her  as  dragging  it  only 
because  she  walked  backward  and  acted  as  though  she 
were  obliged  to  exert  herself.  Quite  often  the  spiders 
taken  by  this  species  are  too  large  to.be  carried,  and 
then  it  is  necessary  to  drag  them;  this  habit  is  so  in- 
grained that  when  it  would  be  much  more  convenient 
to  go  straight  ahead  they  stick  to  the  ancient  custom, 
and  seem  unable  to  move  in  any  other  way.  This  little 
wasp  was  in  a  frantic  hurry,  running  backward  into  the 
223 


WASPS,    SOCIAL   AND    SOLITARY 

Bembex  holes  and  then  scrambling  out  again,  until  she 
had  crossed  the  field  and  had  turned  to  one  side,  having 
gone,  since  we  first  saw  her,  about  fifteen  feet.  Here 
she  dropped  the  spider  and  began  to  skim  over  the 
ground  —  it  could  not  be  called  running  and  yet  it  was 
not  flying  —  until  she  found  a  circular  hole  in  the 
black  earth,  which  looked  as  if  it  ran  vertically  down- 
ward. At  the  time  we  thought  that  this  was  a  nest  that 
she  had  made  for  herself,  but  we  afterward  concluded 
that  it  had  been  excavated  by  some  other  creature, 
that  she  had  found  it  and  determined  to  make  use  of 
it,  and  that  she  was  bringing  her  prey  to  the  spot  with 
that  end  in  view.  Without  entering  she  rushed  back  to 
the  spider,  but  after  carrying  it  a  few  inches,  dropped 
it  and  ran  to  take  another  look  at  the  nest.  By  this 
time,  however,  she  was  too  much  excited  to  know  what 
she  was  about,  and  for  five  minutes  she  scurried  oveF 
the  ground  without  finding  it.  During  this  time  she 
picked  up  the  spider  four  times,  carried  it  a  little  way, 
and  then  dropped  it.  The  last  time  she  carried  it  to  the 
edge  of  the  grass  and  stowed  it  there,  this  being  her  first 
attempt  at  concealment.  She  now  found  the  hole  again 
and  brought  the  spider  nearly  to  it,  but  by  this  time  she 
was  perfectly  beside  herself.  The  spider  was  seized 
again  and  again,  only  to  be  dropped  the  next  second, 
224 


THE    SPIDER-HUNTERS 

while  the  wasp  rushed  back  and  forth  between  it  and 
the  hole.  In  time  this  method  of  procedure  brought 
it  close  to  the  nest,  but  it  was  carried  around  the  edge 
once  or  twice  even  then.  At  last,  accidentally  as  it 
seemed,  it  fell  in,  when  the  wasp  quickly  ran  in  also 
and  pulled  it  down.  For  half  an  hour  she  remained  in- 
side, and  when  she  came  out  we  caught  her  to  make 
sure  of  her  identity.  As  we  set  her  free  immediately 
we  expected  her  to  go  to  work  at  covering  her  nest,  but 
in  this  we  were  disappointed,  for  she  did  not  return. 
We  left  the  place  undisturbed  from  the  thirteenth  to 
the  fifteenth  of  August,  when  we  dug  up  the  nest.  The 
Thomisid  was  there,  but  we  could  find  neither  egg  nor 
larva.  The  spider  was  alive,  as  was  shown  by  a  quiver- 
ing of  the  legs.  This  quivering  grew  fainter  and  fainter, 
until  upon  the  nineteenth  it  was  scarcely  perceptible, 
and  on  the  twenty-first  the  spider  was  dead.  Our  first 
spider  had  been  stung  to  death  at  once,  while  this  one 
lived  seven  days  and  a  half  after  being  stored. 

On  September  first,  while  out  in  the  bean  patch,  we 
saw  a  large  Lycosid  running  madly,  first  in  one  direc- 
tion and  then  in  another.  Hovering  eagerly  and  ex- 
citedly just  above  was  our  marginatus,  dashing  down 
at  the  spider  again  and  again  as  it  came  into  view  for 
an  instant,  and  then  circling  wildly  around  until  it 
225 


WASPS,    SOCIAL   AND    SOLITARY 

appeared  once  more.  Now  she  pounced  upon  the 
frightened  spider  but  missed  her  aim,  now  she  really 
grasped  it  but  was  shaken  off.  At  last  the  end  came. 
The  wasp  descended  upon  the  doomed  spider,  and  there 
was  a  violent  struggle,  both  the  combatants  rolling  over 
and  over  upon  the  ground,  while  all  that  we  could  distin- 
guish was  the  flashing  of  the  red  upon  the  body  of  the 
wasp.  In  an  instant  it  was  over,  and  the  wasp  rose, 
leaving  the  spider  limp  and  motionless  upon  its  back. 
In  our  other  examples  of  marginatus  the  spider  taken 
had  been  so  small  that  the  wasp  might  easily  have  held 
it  and  thrust  her  sting  into  any  spot  that  she  pleased, 
but  this  Lycosid  was  a  different  antagonist.  Where  the 
two  were  so  nearly  matched,  there  could  have  been 
but  slight  opportunity  for  skillful  surgery.  In  point  of 
strength  the  wasp  was  at  a  disadvantage,  and  she 
must  have  come  off  victor  by  the  quick  use  of  her  sting. 
Under  these  circumstances  she  must  have  struck  when 
and  where  she  could,  without  selecting  any  particu- 
lar spot.  That  she  quite  realized  the  power  of  her  foe 
was  shown  by  her  next  action.  With  the  utmost  cir- 
cumspection she  settled  down  upon  the  spider  and 
made  a  prolonged  and  careful  examination  of  the 
mouth  parts.  The  investigation  was  satisfactory,  and 
without  any  further  stinging  she  seized  the  spider  by 
226 


THE    SPIDER-HUNTERS 

one  leg.  and  this  time  really  dragged  it  off.  It  was  a 
good  load  for  her,  and  it  evidently  required  all  of  her 
strength  to  pull  it  along.  Not  far  away  was  a  lump  of 
earth,  under  which  the  treasure  was  stowed;  and  then 
began  the  usual  hunting  performance,  which  soon  re- 
sulted in  the  discovery  of  another  cavity  which  had  a 
very  small  opening. 

She  crept  in,  remained  a  minute,  and  then  came  out 
and  brought  her  spider  to  this  new  hiding-place.  The 
head  went  in  easily,  but  it  took  a  great  deal  of  tugging 
to  get  the  rest  to  follow.  At  last  both  spider  and  wasp 
were  out  of  sight,  and  everything  remained  quiet  for 
so  long  that  we  began  to  think  that  this  time  we  were 
really  to  see  the  final  act  in  the  play.  But  no;  when 
the  little  wasp  came  creeping  out  it  was  only  to  start 
off  on  another  extended  tour,  in  which  we  did  not  at- 
tempt to  follow  her.  She  doubtless  selected  another 
halting-place,  for  when  she  returned  it  was  to  try  to 
get  the  spider  out  of  the  hole  by  pulling  at  one  of  its 
hind  legs.  The  task,  however,  was  not  an  easy  one.  She 
exerted  all  her  strength,  so  that  we  expected  to  see  the 
victim  torn  to  pieces  before  our  eyes,  and  still  it  did 
not  come.  At  last  she  seemed  to  realize  that  there 
was  more  than  one  way  to  accomplish  her  end,  and 
turned  her  attention  to  cutting  away  the  earth  to  make 
227 


WASPS,    SOCIAL   AND    SOLITARY 

the  opening  larger.  After  a  few  moments'  work  she 
tried  again,  and  although  the  passage  was  still  much 
too  small  for  convenience  the  spider  was  at  length 
dragged  forth,  looking  much  the  worse  for  wear.  As 
she  moved  away  we  alarmed  her  by  lifting  some  vines 
that  prevented  our  keeping  her  in  view,  and  she  flew 
up,  leaving  the  spider  on  the  ground.  We  seized  the 
opportunity  to  bend  and  twist  the  plants  this  way  and 
that  so  that  the  ground  might  be  left  uncovered.  The 
changes  that  we  made  probably  disconcerted  her,  for 
she  seemed  to  lose  track  of  her  prey.  For  over  half  an 
hour  she  hunted  about,  circling  above  the  place  and 
running  around  and  around  over  the  ground.  She 
often  came  so  close  to  the  spider  that  we  could  not 
understand  why  she  did  not  see  it.  At  last  it  was  re- 
covered, and  again  she  started  off.  We  tried  to  follow 
her,  but  the  vines  were  so  thick  that,  in  spite  of  our 
efforts,  she  soon  disappeared  into  the  undiscovered 
country  which  we  had  thus  far  been  unable  to  penetrate. 
Up  to  this  time  we  had  been  entirely  unable  to  under- 
stand the  actions  of  marginatus,  and  each  new  example 
added  to  our  confusion  instead  of  clearing  it  away. 
We  were  inclined  to  think  that  she  never  made  a  nest 
for  herself,  but  caught  her  spider  and  then  hurried 
about  for  a  good  place  to  store  it,  and  that  her  absurd 
228 


THE    SPIDER-HUNTERS 

conduct  was  the  result  of  an  indecision  of  character 
which  made  it  extremely  difficult  for  her  to  choose  a 
place  and  be  contented  with  it.  The  last  part  of  this 
judgment  holds  true,  even  now  when  we  know  her  whole 
history,  but  we  have  at  last  learned  that  she  does  dig 
her  own  nest. 

We  had  watched  a  wasp  for  some  time  as  she  car- 
ried her  spider  from  place  to  place,  and  finally  saw 
her  take  it  into  a  crevice  among  some  rough  lumps  of 
earth  which  she  had  previously  examined.  We  ex- 
pected one  of  the  long  spells  of  eventless  waiting  to 
which  she  had  accustomed  us,  but  on  lying  down  and 
peering  into  the  hole  we  found  that  there  was  an  open- 
ing on  the  further  side,  for  a  ray  of  light  feebly  penetrated 
the  interior.  Moving  about  in  this  dim  illumination 
was  our  wasp,  and  after  a  little,  we  could  see,  quite 
distinctly,  that  she  was  digging  a  hole.  This  then  is 
her  method  —  to  find  some  sheltered  hiding-place 
where  she  may  secretly  make  her  nest,  that  no  creature 
may  know  where  her  treasure  is  hidden. 

We  have  twice  seen  a  marginatus  pick  up  her  spider 
and  fly  with  it  backward  for  a  long  distance  —  as  much 
as  four  or  five  feet.  This  recalls  the  wasp  which  is  said 
to  fly  backward  before  a  moving  horse  and  catch  the 
flies  that  are  hovering  over  it. 
229 


WASPS,    SOCIAL    AND    SOLITARY 

P.  marginatus  is  not  troubled  by  any  notion  as  to 
the  family  connections  of  the  spider  that  she  takes. 
Anything  will  do  provided  she  is  strong  enough  to  over- 
come it  and  carry  it  to  her  nest.  The  effect  of  her  sting 
is  quite  variable,  since  in  some  cases  the  victim  was 
killed  at  once,  while  in  others  it  was  but  little  affected 
in  the  beginning  and  lived  for  eighteen  or  twenty  days. 

At  eleven  o'clock  on  the  morning  of  a  warm  day  in 
mid-August  we  saw  the  steel-blue  Pompilus  scelestus 
dragging  a  big  Lycosid  across  a  field.  The  spider  was 
sixteen  millimeters  long  and  wide  in  proportion,  while 
the  wasp  was  but  thirteen  millimeters  long  and  very 
slender,  so  that  the  weight  of  the  spider  was  at  least 
three  times  that  of  its  captor.  The  necessity  for  going 
backward  was  evident  in  this  case,  but  the  wasp  moved 
rapidly  considering  the  load  that  she  was  dragging. 
As  she  worked  her  way  along  she  made  frequent  pauses, 
stopping  for  two  or  three  minutes  at  a  time  in  some  little 
hollow,  or  under  leaves  or  weeds.  She  spent  a  good 
deal  of  time,  during  these  pauses,  in  cleaning  herself, 
and  a  good  deal  of  time  also  in  doing  something  to  the 
spider  which  we  could  not  understand.  She  seemed  to 
be  biting  the  legs,  near  the  body,  beginning  with  an  an- 
terior leg  on  one  side  and  working  backward,  and  then 
repeating  the  operation  on  the  other  side.  She  went 
230 


THE    SPIDER-HUNTERS 

through  this  squeezing  process  again  and  again,  and 
to  us  it  looked  as  though  she  might  be  trying  to  force 
back  the  juices  from  the  legs  into  the  body  preparatory 
to  cutting  them  off;  but  after  a  time  she  would  seize  her 
prey  and  start  on  again.  She  had  made  her  way  along 
in  this  fashion  for  some  ten  feet,  when  a  second  wasp 
appeared  and  alighted  on  a  weed  near  by.  This  inter- 
loper was  a  trifle  smaller  than  the  other,  and  from  her 
actions  was  evidently  greatly  interested  in  the  paralyzed 
spider.  When  the  Pompilus  stopped  for  a  moment  the 
other  moved  from  stem  to  stem  in  a  stealthy  manner 
just  as  a  cat  stalks  a  bird.  The  rightful  owner  of  the 
prey  was  disturbed  and  dashed  at  her,  driving  her  away 
again  and  again,  but  she  flew  only  a  short  distance  and 
was  soon  back,  always  creeping  nearer  and  nearer  to 
the  spider.  We,  too,  were  watching  with  closest  atten- 
tion, but  our  desire  was  to  see  the  speedy  homecoming 
of  Pompilus  and  to  learn  whether  she  cut  off  the  legs 
of  her  victim;  and  so,  interesting  as  was  the  contest 
between  the  wasp  and  the  wasp-inquiline,  we  decided 
to  interfere  and  remove  the  intruder.  This  was  very 
easily  accomplished,  since  the  little  insect  was  so  intent 
upon  following  the  spider  that  she  was  oblivious  to  our 
presence,  and  allowed  us  to  place  a  bottle  over  her  as 
she  stood  eagerly  looking  for  a  chance  to  advance.  Her 
231 


WASPS,    SOCIAL    AND    SOLITARY 

removal  gave  great  relief  to  the  other  wasp,  as  was 
manifested  by  an  entire  change  of  manner.  Before,  she 
had  been  constantly  on  the  lookout,  moving  only  with 
the  greatest  circumspection,  but  now  she  relaxed  her 
vigilance.  With  the  Ceropales  in  our  vial  we,  too,  felt 
relieved,  and  now  the  path  of  discovery  seemed  clear 
before  us  ;  but  scarcely  had  things  assumed  their  old 
status  when  a  second  enemy,  a  much  larger  and  bolder 
Ceropales,  threw  both  the  Pompilus  and  ourselves  into 
consternation.  Again  we  took  the  side  of  our  wasp  and 
drove  the  other  one  off,  but  only  to  see  it  return  a  few 
moments  later.  The  Pompilus  now  flew  at  it  in  a  most 
gallant  fashion  and  pursued  it  far  afield,  but  when  she 
came  back  the  enemy  was  but  a  few  seconds  behind 
her.  Here  we  again  interposed  and  removed  the  second 
Ceropales  from  the  field  of  action. 

All  cause  for  anxiety  being  over,  the  wasp  now  re- 
sumed her  journey.  Before  long  she  came  to  a  shallow 
depression  in  the  ground  which  was  partly  sheltered  by 
an  overhanging  lump  of  earth,  and  under  this  covering 
she  dropped  the  spider  and  again  began  to  squeeze  its 
legs.  After  a  moment  she  removed  it  to  the  other  side 
of  the  depression,  where  it  was  subjected  to  further 
manipulation.  Next,  her  toilet  was  attended  to,  and 
then  the  spider  was  carried  back  and  placed  again 
232 


THE    SPIDER-HUNTERS 

under  the  lump  of  earth.  At  least  ten  times  was  that 
limp  and  helpless  creature  dragged  from  one  side  to 
the  other  of  the  little  depression,  a  distance  of  about 
two  inches,  the  time  between  being  filled  in  by  the  wasp 
with  cleaning  herself  and  squeezing  the  legs  of  her 
victim.  After  forty  minutes  of  this  tedious  delay  the 
moment  came  when  she  picked  up  her  burden  with 
renewed  determination  and  started  rapidly  on  her  way. 
We  kept  very  close  to  her,  but  she  did  not  allow  our 
presence  to  interrupt  her  work,  and,  indeed,  paid  no 
attention  to  it.  After  she  had  gone  along  for  a  distance 
of  about  eight  feet  there  was  another  pause,  of  only 
five  minutes  this  time,  and  when  she  resumed  her  on- 
ward march  it  was  in  a  new  direction.  Thus  far  she 
had  gone  almost  due  south,  but  now  she  turned  and 
went  six  feet  toward  the  west.  Suddenly  the  spider 
was  dropped.  There  was  no  hole  in  sight,  but  the  wasp 
seemed  to  feel  that  some  important  crisis  had  arrived. 
Her  whole  manner  was  excited  and  flurried,  and  we 
thought  that  surely  we  had  reached  the  neighborhood 
of  the  nest.  How  little  we  understood  her!  Her  nest  was 
still  far  away,  and  it  may  be  that  she  had  just  begun  to 
realize  that  the  task  she  had  undertaken  was  too  heavy 
for  her  accomplishment — that  at  her  present  rate  of  pro- 
gress her  strength  would  be  exhausted  before  she  could 
233 


WASPS,    SOCIAL    AND    SOLITARY 

reach  her  goal.  At  any  rate,  something  was  wrong.  The 
spider  was  left  unprotected  on  the  ground  while  she 
made  a  number  of  long  excursions  without  it,  sometimes 
being  gone  as  much  as  fifteen  minutes.  On  coming 
back  from  these  trips  she  would  return  to  the  task  of 
squeezing  the  legs  with  such  energy  and  persistence 
that  we  expected  to  see  them  drop  off.  Then  she  would 
run  over  the  ground  in  all  directions,  looking  under 
lumps  of  earth  and  stones  and  poking  her  head  into 
every  little  hole.  Was  she  trying  to  find  some  suitable 
spot  near  at  hand  to  take  the  place  of  the  one  which 
she  had  prepared  or  selected  at  a  distance? 

One  hour  from  the  time  of  her  arrival  at  this  place, 
and  two  hours  from  the  time  that  we  began  to  watch 
her,  she  flew  away  and  was  gone  for  an  unusually  long 
time.  We  can  only  suppose  that  when  she  absented 
herself  in  this  way  she  was  visiting  the  spot  to  which 
she  wished  to  convey  her  booty.  On  her  return  she  seemed 
to  be  filled  with  a  new  idea,  for  after  climbing  to  the 
top  of  a  tall  stout  weed  that  grew  near  by,  she  came 
down,  seized  the  spider,  and  tried  to  drag  it  up  the  stem. 
Perhaps  she  meant  to  lift  it  to  such  an  elevation  that 
she  could  fly  with  it,  but  it  was  too  heavy  for  her  and 
fell  after  she  had  raised  it  to  a  height  of  three  inches. 
She  then  flew  away  again,  and  on  her  return  we  caught 
234 


THE    SPIDER-HUNTERS 

her,  fearing  that  she  was  becoming  discouraged  and 
that  she  might  presently  depart  to  be  seen  no  more. 
Had  there  been  any  prospect  of  her  solving  the  diffi- 
culty that  beset  her  our  patience  might  have  held  out 
to  the  end,  but  this  was  evidently  a  case  in  which  there 
was  a  failure  of  instinct,  or  intelligence,  or  whatever 
faculty  was  concerned. 

More  than  a  year  passed  before  we  had  another  op- 
portunity of  solving  this  problem  of  scelestus,  and  the 
pleasure  with  which  we  hailed  her  second  appearance 
in  our  garden  may  be  easily  imagined.  This  time  the 
wasp  had  made  her  nest,  but  was  not  ready  to  fill  it,  and 
when  we  first  saw  her  she  was  running  about  without 
any  particular  aim  in  view,  although  at  the  tune  we 
supposed  her  to  be  hunting.  Before  long  she  went  and 
took  a  look  at  the  neat  round  hole  which  she  had  made 
near  the  fence  that  separates  the  garden  from  the  woods. 
The  earth  that  had  been  taken  out  either  had  been 
carried  to  a  distance  or  had  been  swept  away  after  the 
digging  was  completed,  for  there  was  no  pile  to  be  seen. 
This  was  at  two  o'clock  of  a  cloudy  afternoon.  It  may 
be  that  she  needed  the  stimulus  of  sunshine  to  make 
her  hunt,  or  perhaps  she  realized  that  what  was  left  of 
the  day  would  not  give  her  sufficient  time  to  capture  her 
spider  and  bring  it  home.  At  any  rate,  she  spent  the 
235 


WASPS,    SOCIAL   AND    SOLITARY 

remainder  of  the  afternoon  in  making  short  excursions 
around  her  nest,  attended,  at  a  little  distance,  by  a 
smaller  blue  wasp,  Pompilus  subviolaceus,  whose  pre- 
sence she  did  not  seem  to  notice.  These  trips  took  her 
from  ten  to  twenty  feet  from  the  nest,  each  occupying 
from  fifteen  minutes  to  half  an  hour.  At  every  return 
to  the  nest  she  flattened  herself  out  on  the  ground  and 
wriggled  in  the  dust,  and  then  dragged  herself  all 
around  it  in  the  strangest  manner.  Perhaps  these  ac- 
tions were  indications  of  pleasurable  emotion.  We  had 
seen  them  once  before,  in  Priononyx  atrata  just  before 
she  carried  a  locust  into  her  nest. 

At  a  little  after  four  o'clock  she  began  to  investigate, 
very  carefully,  the  plants  and  grasses  that  immediately 
surrounded  her  hole,  showing  an  especial  interest  in 
one  bunch  of  clover  that  grew  four  inches  away.  Into 
this  she  finally  vanished,  and  peering  curiously  among 
the  greenery,  we  discovered  her  hanging  to  a  leaf,  which 
was  sheltered  by  thick  foliage  on  all  sides.  Here  she 
remained  motionless  and  probably  fast  asleep  until 
sundown,  when  we  left  her  for  the  night. 

When  we  went  to  the  garden  at  eight  o'clock  on  the 

following   morning,    subviolaceus   was   on   hand,  but 

scelestus  was  still  sound  asleep  in  her   leafy  bower. 

We  thought  it  best  to  awaken  her,  for  a  large  spider 

236 


THE   SPIDER-HUNTERS 

had  spread  its  web  just  below,  and  if  the  wasp  should 
drop  upon  it  nothing  could  save  her.  We  therefore 
aroused  her  gently,  whereupon  she  crept  slowly  up  the 
stem  and,  taking  her  stand  on  the  highest  point,  sur- 
veyed the  world.  Then,  after  stretching  herself  sleepily, 
she  made  her  toilet,  cleaning  off  her  wings  and  legs, 
and  washing  her  face  with  her  feet  like  a  cat.  When 
these  duties  were  finished  she  walked  slowly  about  for 
an  hour,  visiting  her  nest  every  now  and  then.  Sud- 
denly, at  half  past  nine  o'clock,  her  whole  manner 
changed,  and  seeming  very  much  excited  she  ran  rapidly 
along,  parallel  with  the  fence,  for  fifteen  or  twenty  feet, 
and  then,  rising  on  her  wings,  flew  far  away  into  the 
woods.  She  had  evidently  gone  hunting  at  last,  and 
we  watched  eagerly  for  her  return.  She  was  not  suc- 
cessful at  once,  however,  for  at  half  past  ten  she  came 
back  without  anything,  stayed  at  the  nest  for  a  few 
minutes,  and  then  flew  to  the  woods  again  with  the 
same  excited  manner  as  before.  Perhaps  she  had  al- 
ready caught  her  spider  at  some  far  distant  spot,  and 
was  getting  her  bearings  preparatory  to  bringing  it 
home  ;  but  it  was  half  past  one  when  she  suddenly  ap- 
peared, five  or  six  inches  from  the  nest,  coming  back- 
ward through  the  fence,  and  dragging  a  large  Lycosid. 
This  she  laid  down  close  by,  and  began  to  bite  at  the 
237 


WASPS,    SOCIAL   AND    SOLITARY 

legs  quite  after  the  manner  of  the  wasp  we  had  seen 
the  year  before.  Her  movements  were  full  of  nervous 
excitement,  in  marked  contrast  to  those  of  the  previous 
day.  Presently  she  went  to  look  at  her  nest,  and  seemed 
to  be  struck  with  a  thought  that  had  already  occurred 
to  us  —  that  it  was  decidedly  too  small  to  hold  the 
spider.  Back  she  went  for  another  survey  of  her  bulky 
victim,  measured  it  with  her  eye,  without  touching  it, 
drew  her  conclusions,  and  at  once  returned  to  the  nest 
and  began  to  make  it  larger.  We  have  several  times  seen 
wasps  enlarge  their  holes  when  a  trial  had  demonstrated 
that  the  spider  would  not  go  in,  but  this  seemed  a  re- 
markably intelligent  use  of  the  comparative  faculty. 
Her  method  of  work  was  peculiar.  Standing  in  the  tun- 
nel with  her  head  down  and  her  abdomen  curved  under, 
she  bit  the  earth  loose  with  her  mandibles  and  pushed 
it  under  her  body  and  beyond  the  tip  of  the  abdomen. 
When  a  little  had  accumulated  she  backed  out,  holding 
it  in  this  way. 

While  she  was  thus  employed  the  spider  was  attacked 
by  a  very  tiny  red  ant,  that  could  not  by  any  possibility 
have  stirred  it.  When  the  wasp  caught  sight  of  this 
insignificant  marauder  she  fell  into  a  fit  of  wild  fury, 
and  bending  her  abdomen  under,  seized  the  ant  again 
and  again  in  her  mandibles,  and  flung  it  backward 
238 


THE   SPIDER-HUNTERS 

against  the  tip  of  her  sting.  The  little  creature  finally 
escaped,  seeming  none  the  worse  for  the  rough  han- 
dling to  which  it  had  been  subjected,  while  the  wasp, 
still  trembling  with  excitement,  grasped  her  spider  and 
rushed  off  to  a  distance  of  several  feet,  carrying  it  up 
on  a  weed  and  depositing  it  there.  The  labor  of  ex- 
cavation was  then  resumed,  and  after  a  half-hour's 
work  the  nest  was  completed  to  her  satisfaction. 

Coming  up  head  first,  she  flattened  herself  out  on 
the  ground,  and  sprawling  thus,  dragged  herself  all 
around  it.  The  spider  was  now  brought  to  the  nest, 
being  left  once  on  the  way  while  she  ran  in  and  out  again, 
and  was  taken  in  after  a  new  and  original  fashion. 
Backing  in  herself,  she  seized  it  by  the  tip  of  the  abdo- 
men and  dragged  it  down  without  any  trouble,  since 
the  legs  were  gently  pushed  up  over  the  head  and  made 
no  resistance. 

In  two  minutes  she  emerged  from  the  opening,  and 
standing  on  the  four  posterior  legs,  with  her  abdomen 
hanging  down  into  the  hole,  scratched  the  earth  back- 
ward with  the  front  legs  and  mandibles.  As  it  fell  in 
she  pushed  it  down  with  the  abdomen,  and  as  the  hole 
filled  she  raised  herself  higher  and  higher  on  her  legs, 
still  using  the  tip  of  the  abdomen  to  work  the  material 
into  place. 

239 


WASPS,    SOCIAL   AND    SOLITARY 

When  the  filling  of  the  nest  was  nearly  completed, 
we  caught  the  wasp,  and  after  taking  the  spider,  threw 
back  the  earth  into  the  hole.  Subviolaceus,  who  had 
watched  the  homecoming  from  a  respectful  distance, 
now  felt  that  her  turn  had  come,  and  descending  upon 
the  spot  began  to  dig.  Not  finding  anything,  she  shifted 
her  position  several  times,  and  worked  industriously, 
even  returning  after  we  had  frightened  her  away. 
Sharp  says  that  a  Ceropales  has  been  observed  to  ovi- 
posit on  a  spider,  not  while  it  was  being  carried  in,  but 
subsequently  by  entering  the  nest  for  the  purpose; 
and  the  actions  of  subviolaceus  pointed  to  similar  in- 
tentions on  her  part.  We  have  watched  her  for  an  hour 
at  a  time  running  into  the  open  nests  on  the  Bembex 
field,  sometimes  coming  out  again  directly  and  some- 
times remaining  inside  for  several  minutes.  It  is  not 
likely  that  she  would  utilize  the  flies  of  Bembex,  but 
it  may  be  that  she  was  looking  for  the  Pompelid  nests 
that  are  often  made  in  the  same  locality.  Scelestus  did 
not  notice  subviolaceus,  and  it  is  difficult  to  see  why  a 
wasp  should  be  disturbed  by  the  presence  of  a  para- 
site. In  making  and  storing  her  nest  she  is  the  blind 
instrument  of  an  impelling  power ;  she  knows  what  she 
must  do,  but  not  why  she  does  it.  Her  descendants  are 
in  most  cases  as  completely  outside  of  her  experience 
240 


THE   HOME-COMING  OF  SCELESTUS 


THE  SPIDER-HUNTERS 

as  her  ancestors,  and  how  should  she  guess  that  the 
presence  of  a  certain  fly  or  wasp  means  danger  to  her 
race?  Of  what  happens  to  her  egg  after  she  leaves  it 
she  is  so  absolutely  ignorant  that  she  might  easily  look 
on  with  serene  indifference  at  the  destruction  of  her 
own  larva  by  that  of  the  intruder.  In  Astata  we  see,  as 
might  be  expected,  a  calm  tolerance  of  the  visits  of  the 
Chrysis  fly,  but  the  uneasiness  of  scelestus  herself  at 
the  sight  of  Ceropales  and  the  valorous  defense  of  Try- 
poxylon  show  more  highly  developed  instincts.  Bem- 
bex,  too,  deeply  resents  the  presence  of  parasites,  al- 
though after  the  deed  is  done  she  feeds  their  young 
without  questioning  their  right  to  her  care.  Among 
bees,  Andrena,  and  Nomada,  which  is  parasitic  upon  it, 
are  said  to  live  on  most  friendly  terms;  but  in  other 
genera  there  is  a  deep-seated  enmity  between  host  and 
parasite. 

In  the  literature  of  the  Hymenoptera  references  have 
been  made  from  time  to  time  to  certain  wasps  that  cut 
off  the  legs  of  spiders  or  other  creatures  before  storing 
them  away;  but  observations  on  the  subject  have  been 
rare  and  not  very  definite.  Brehm,  in  the  "Thier- 
leben,"  says  that  Agenia  punctata  builds  nests  of  mud, 
and  places  in  each  cell  one  moderately  large  spider 
from  which  she  has  first  removed  all  the  legs.  The 
243 


WASPS,    SOCIAL   AND    SOLITARY 

most  interesting  notes  on  the  subject  have  been  made 
by  M.  Goureau,  who  gives  an  account  of  finding  two 
spiders  that  had  been  mutilated  by  wasps,  one  of  them 
having  had  all  of  the  legs  cut  off,  and  the  other  all  but 
the  first  pair.  At  another  time  a  wasp  that  was  flying 
near  him  let  fall  a  spider,  which  he  captured  before  it 
could  be  recovered  by  the  owner.  The  wasp  escaped, 
so  that  he  could  not  determine  the  species,  but  the 
spider's  legs  had  been  removed.  He  concluded  that  in- 
stead of  stinging  the  spiders  the  wasps  had  mutilated 
them  so  that  they  could  not  run  away.  He  does  not  seem 
to  realize  that  death  would  certainly  result  from  such 
an  operation. 

Vespa  germanica  often  cuts  off  the  wings  of  a  dead 
wasp,  or  even  cuts  its  body  into  two  parts,  before  flying 
away  with  it,  but  this  is  only  when  the  captured  insect 
is  too  large  to  be  handled  in  any  other  way;  and  Pom- 
pilus  fuscipennis  sometimes  cuts  off  one  or  more  legs 
from  her  spider,  although  without  any  regular  method 
of  procedure. 

Agenia  bombycina  finds  a  nesting -place  to  her  liking 
on  our  smoke-house,  in  the  crevice  between  the  bricks 
and  the  wooden  door-frame,  where  she  makes  clusters 
of  little  mud  cells,  putting  one  mutilated  spider  into 
each,  and  storing  about  one  a  day.  Her  locality  sense 
244 


THE  SPIDER-HUNTERS 


NEST  OF  AGENIA 
BOMBYCINA 


is  unusually  poor,   owing  apparently  to   her  intense 
nervousness  and  excitability,  but  some 
individuals    are    better   endowed   than 
others  in  this  respect. 

On  a  bright  morning  in  the  middle 
of  August  we  stationed  ourselves  by  the 
smoke-house  at  eight  o'clock,  and  half 
an  hour  later  an  Agenia  began  to  bring 
lumps  of  earth,  working  out  of  sight 
under  the  door  frame.  She  kept  at  it 
steadily,  spending  three  or  four  minutes  in  getting  a 
load  and  one  or  two  in  placing  it.  At  twelve  o'clock, 
her  nest  being  ready,  she  flew  away  to  hunt 
for  a  spider.  So  long  as  a  wasp  conies 
and  goes  at  frequent  intervals  time  slips 
away  rapidly,  but  to  keep  one's  attention 
unflagging  through  hours  of  watching  is 
weariness  to  the  flesh.  We  saw  no  more 
of  our  Agenia  until  three,  when  she  ap- 
peared, half  walking,  half  flying  through 
the  grass,  going  forward.  Her  spider  was  LYCOSA  KOCH". 

FOUND  TN  NEST 

held  by  the  spinnerets,  and  being  larger    OF  AGENIA  BOM- 
than  she  was  it  trailed  behind  her.    On    BYCINA 
reaching  the  wall  she  began  to  climb ;  but  the  weight  of 
the  spider  made  her  fall  again  and  again,  and  forty 
245 


WASPS,    SOCIAL    AND    SOLITARY 

minutes  passed  in  wearisome  toil  before  it  was  safely  put 
away.  The  egg  having  been  laid,  she  began  to  bring 
earth  for  closing,  and  we  felt  thankful  that  our  task  as 
well  as  hers  was  nearly  over.  She  worked  slowly  now, 
taking  ten  or  fifteen  minutes  for  a  trip;  but  after  bringing 
in  the  sixth  pellet  she  took  on  a  livelier  air,  and  before 
long  we  were  convinced  that  she  had  begun  to  build 
a  new  cell.  For  two  hours  longer  we  watched  her  un- 
remitting labor,  and  when  we  left  her  at  six  o'clock  she 
was  flying  back  and  forth  as  briskly  as  ever. 

Another  Agenia,  less  ambitious,  brought  her  spider 
at  three  o'clock  and  then  went  to  bed  in  an  empty  cell, 
head  in,  tail  sticking  out.  We  cut  away  a  section  of  the 
door-frame  that  covered  the  spot  without  disturbing 
her  slumber.  This  one  could  never  remember  where 
her  nest  was,  but  had  a  long  hunt  for  it  every  time 
she  brought  a  pellet ;  and  when  she  had  caught  the 
spider  she  lost  herself  completely  on  the  brick  wall, 
going  to  the  very  top,  and  even  around  the  corner 
on  to  the  side  of  the  building.  Every  little  while  she 
would  fly  back  to  the  grass  at  the  threshold  and  start 
up  afresh,  and  in  this  way  she  finally  stumbled  on 
the  right  spot  by  accident.  This  seemed  very  stupid 
of  her,  as  she  made  many  locality  studies.  Her  be- 
havior was  in  striking  contrast  to  little  Rhopalum's 
246 


THE   SPIDER-HUNTERS 

unerring  choice  of  one  tiny  pin-hole  among  hundreds 
just  like  it. 

The  larva  of  bombycina  cocoons  nine  days  after  the 
egg  is  laid.  The  spiders  that  we  found  in  the  cells  were 
dead  even  when  taken  on  the  day  of  storing.  There 
was  no  rule  about  the  degree  of  mutilation,  one  having 
seven  legs  left,  two  five,  one  two,  and  four  none.  We 
have  no  doubt  that  the  object  of  this  curious  habit  is  to 
save  room  in  the  nest. 


Chapter  X 

THE    ENEMIES    OF    THE    GRASSHOPPER 

EARLY  in  September  a  little  black  Tachytes  sud- 
denly became  very  common  in  the  garden.  The 
first  one  that  we  saw  was  going  forwards  in  a  series  of 
long  jumps,  carrying  a  small  grasshopper  which  was 
held  by  the  base  of  the  antennae.  She  soon  doubled  on 
her  tracks,  and  it  became  evident  that  she  did  not  know 
her  way;  but  after  going  about  in  circles  for  two  min- 
utes she  ran  into  her  nest.  When  she  came  out  she 
spent  a  long  time  in  circling  around,  flying  close  to  the 
ground  in  wavy,  snaky  lines,  occasionally  alighting  to 
run  a  few  steps ;  but  in  spite  of  this  locality  study,  ten 
minutes  later,  when  she  came  jumping  along  with  her 
second  grasshopper,  she  had  lost  her  nest  again  and 
hunted  about  just  as  before,  twice  going  directly  over 
it  without  seeing  it.  While  she  was  thus  occupied  an- 
other wasp  of  the  same  species  attacked  her  and  tried 
to  get  possession  of  the  grasshopper,  but  the  rightful 
owner  was  able  to  defend  it.  At  last  it  was  stored  away, 
248 


THE    ENEMIES    OF   THE    GRASSHOPPER 

and  she  proceeded  to  fill  the  nest,  scratching  the  earth 
in  with  her  first  legs  and  working  it  down  with  the  tip 
of  the  abdomen.  She  worked  quietly  but  steadily  for 


ten  minutes,  closing  the  place  neatly,  and  then  brought 
bits  of  leaf  and  pieces  of  earth  to  cover  it  all  over. 

On  the  same  afternoon  we  saw  another  of  these  wasps 
digging  her  nest,  but  she  was  so  much  disturbed  when 
we  came  anywhere  near  her  that  we  were  obliged  to 
retire.  On  the  next  day  we  saw  her  astride  of  a  small 
grasshopper,  jumping,  along  like  the  one  of  the  day 
before.  She  too  had  great  trouble  in  finding  her  way. 
When  she  reached  the  nest  she  laid  her  prey  down 
while  she  went  inside  for  a  moment,  and  then,  coming 
249 


WASPS,    SOCIAL    AND    SOLITARY 

out,  seized  it  by  the  antennae  and  backed  in  with  it, 
instead  of  taking  it  in  forwards  as  was  done  in  the  other 
case. 

Another  wasp  of  this  species  carried  a  much  larger 
grasshopper,  which  was  so  heavy  that  she  could  not 
jump  with  it,  but  was  obliged  to  keep  to  the  ground. 
In  this  case  only  one  was  used  instead  of  two,  which  is 
the  usual  number.  This  wasp  was  first  seen  at  a  distance 
of  twenty  feet  from  her  nest,  and  yet  she  went  straight 
to  the  right  spot  without  the  least  confusion,  showing 
that  some  individuals  of  the  species  have  a  better  idea 
of  locality  than  others. 

The  nest  is  a  short,  shallow  tunnel  with  an  enlarge- 
ment at  the  end,  within  which  are  placed  the  grass- 
hoppers, on  their  backs,  with  their  heads  in.  Earth  is 
packed  solidly  into  the  tunnel,  but  not  into  the  cavity 
at  the  end. 

We  took  two  eggs  of  this  species.  Each  was  placed 
across  the  thorax  of  the  grasshopper  at  the  base  of  the 
neck,  on  the  ventral  side.  Both  hatched  at  the  end  of 
thirty-six  hours  from  the  time  they  were  laid,  ate  for 
three  days,  and  then  spun  their  cocoons.  One  of  them 
ate  only  one  small  grasshopper,  leaving  a  second  one 
untouched,  while  the  other  finished  the  large  grass- 
hopper that  formed  her  sole  provision. 
250 


THE    ENEMIES    OF   THE    GRASSHOPPER 

The  grasshoppers  taken  from  the  nests,  five  in  num- 
ber, were  in  all  cases  alive,  there  being  a  quivering  of  the 
mouth  parts,  and  in  some  cases  of  the  legs  also,  without 
any  stimulation.  This  condition  lasted  for  twenty-four 
hours  from  the  time  the  poison  was  injected.  After 
that  they  became  quiet,  but  remained  alive  until  they 
were  destroyed  by  the  larvae. 

It  is  a  curious  thing  that  in  these  wasps  is  found  the 
perfection  of  that  method  of  paralyzing  the  prey  which 
is  so  much  dwelt  upon  by  Fabre,  although  from  their 
habits  this  fine  workmanship  is  not  of  the  slightest  use 


NEST   OF   TACHYTES 


to  them.  They  entomb  their  victims  underground, 
where  the  conditions  are  favorable  to  their  preservation, 
and  the  extremely  short  period  that  elapses  between 

25 * 


WASPS,    SOCIAL    AND    SOLITARY 

the  laying  of  the  egg  and  the  spinning  of  the  cocoon 
makes  it  a  matter  of  indifference  whether  the  grass- 
hopper is  alive  or  dead,  since  in  any  case  it  would  be 
eaten  before  decomposition  set  in. 

We  deserve  no  credit  for  discovering  a  second  species, 
Tachytes  peptonica,  for  by  her  loud  buzzing,  slow  flight, 
and  persistent  hovering  over  the  nest  she  gave  us  every 
assistance  in  her  power.  She  looks  and  acts  like  one 
of  the  large  leaf-cutting  bees,  and  this  resemblance  is 
heightened  by  the  fact  that  the  grasshopper  which  she 
carries  is  frequently  of  a  leaf-green  color.  Her  nest, 
which  is  sometimes  on  the  bare  ground  and  sometimes 
in  the  grass,  has  no  external  sign  to  mark  it,  and  when 
with  a  great  deal  of  fuss  and  buzzing  she  descends 
and  burrows,  it  closes  behind  her  and  disappears  from 
view,  so  that  unless  one  marks  the  exact  spot  there  is 
no  way  of  detecting  it  afterward.  On  her  exit  a  very 
slight  amount  of  scratching  closes  the  hole  and  leaves 
it  looking  exactly  like  the  surrounding  surface;  so  that 
in  comparing  her  work  with  the  protracted  labor  of 
Ammophila  and  some  species  of  Pompilus  in  disguis- 
ing the  locality  of  the  nest,  we  were  struck  by  the  suc- 
cess to  which  she  attained  with  a  very  trifling  amount 
of  effort. 

It  takes  peptonica  thirty  or  forty  minutes  to  catch 
252 


THE    ENEMIES    OF    THE    GRASSHOPPER 

a  grasshopper,  and  at  each  visit  she  remains  for  ten  or 
fifteen  minutes  inside  the  nest.  The  grasshopper  is  car- 
ried in  the  mandibles,  supported  by  the  second  and  third 
pairs  of  legs.  We  never  succeeded  in  opening  a  nest  of 
this  species,  but  a  grasshopper  taken  as  the  wasp  was 
bringing  it  home  did  not  die  until  the  sixth  day. 

In  our  summer  work  we  often  found  ourselves  wish- 
ing that  we  could  be  in  half  a  dozen  places  at  once 
and  could  chase  several  wasps  at  the  same  time.  Never 
did  we  feel  these  desires  more  keenly  than  on  the  twenty- 
ninth  of  July,  when,  after  spending  the  best  part  of  an 
hour  in  watching  the  hunting  of  an  Ammophila,  we  were 
obliged  to  choose  between  following  her  to  a  possible 
conclusion,  and  giving  our  attention  to  a  little  jet-black 
wasp,  Lyroda  subita,  which  we  now  saw  for  the  first 
time.  This  wasp  was  running  around  a  bunch  of  clover 
in  a  nervous,  agitated  manner,  as  though  she  were 
oppressed  by  some  great  anxiety.  The  chance  of  dis- 
covering something  entirely  new  decided  us  to  relinquish 
our  Ammophiline  hopes,  and  we  sat  down  at  the  feet  of 
our  new  teacher. 

We  could  not  see  anything  remarkable  about  that 

bunch  of  clover,  but  certainly  the  spot  had  some  strong 

attraction  for  the  uneasy  little  wasp.    She  ran  of!  first 

in  one  direction  and  then  in  another.   She  circled  about 

253 


WASPS,    SOCIAL    AND    SOLITARY 

and  made  short  flights  now  this  way  and  now  that,  but 
always  returned.  At  last  she  betrayed  the  secret  of  her 
interest  by  descending  to  the  ground  and  picking  up  a 
small  black  cricket  which  had  been  lying  close  by  all  the 
time.  She  flew  up  into  the  air  with  it,  but  even  now  did 
not  leave  the  neighborhood,  continuing  to  fly  about  from 
place  to  place,  alighting  now  and  again  on  the  bean 
plants. 

After  this  performance  had  lasted  for  five  minutes 
she  brought  her  burden  back  to  the  same  spot  that  it 
had  occupied  before,  laid  it  down,  and  without  vouch- 
safing to  us  any  explanation  of  her  conduct,  began  to 
burrow  into  the  soft  earth.  She  went  down  head  first, 
backing  out  with  the  dirt,  which  she  carried  with  the 
front  legs.  While  she  was  thus  occupied  we  defended 
her  booty  against  two  hunting  parties  of  ants  which,  at 
different  times,  fell  upon  it  and  would  certainly  have 
carried  it  off  if  we  had  not  been  at  hand. 

It  took  the  wasp  twenty  minutes  to  open  the  burrow, 
although,  as  we  afterward  learned,  it  had  been  exca- 
vated before.  At  the  end  of  that  time  she  turned  around 
inside,  came  out  head  first,  and  dragged  the  cricket 
within. 

We  at  once  opened  the  nest,  but  found  it  impossible 
to  follow  the  tunnel  on  account  of  the  crumbling  of 
254 


THE    ENEMIES    OF   THE    GRASSHOPPER 

the  earth.  Indeed,  we  almost  concluded  that  we  were 
doomed  to  complete  failure,  for  it  was  not  until  we  had 
gone  down  between  six  and  seven  inches  that  we  found,  in 
a  little  pocket,  our  wasp  in  company  with  three  crickets, 
upon  one  of  which  was  a  larva  a  day  or  two  old.  At  the 
time  we  knew  nothing  of  the  habits  of  Bembex  spinolae, 
and  we  were  much  astonished  to  find  a  wasp  which  evi- 
dently fed  her  young  from  day  to  day. 

The  contents  of  the  nest  were  carefully  conveyed  to  our 
wasp-nursery  at  the  cottage.  The  cricket  that  we  had 
seen  taken  in  was  dead,  as  was  also  the  one  upon  which 
the  larva  was  feeding.  The  third  one  was  alive,  as  was 
shown  by  a  rhythmic  movement  of  the  palp  on  the  right 
side.  By  the  next  day,  however,  this  one  also  was  dead. 

On  the  morning  of  the  third  day,  July  thirty-first, 
the  larva  had  eaten  all  of  the  first  cricket  and  the  greater 
part  of  one  of  the  others,  leaving  only  the  large  hind  legs. 
Supplying  the  place  of  the  mother,  we  killed  two  more 
and  put  them  into  the  tube.  One  of  these  was  eight 
millimeters  long,  this  being  about  the  size  of  those  which 
the  wasp  herself  had  caught,  while  the  other  was  of 
another  species  and  much  larger,  being  thirty  milli- 
meters long.  Its  size  and  kind,  however,  made  no  differ- 
ence to  the  larva,  which  attacked  this  one  next,  although 
there  were  two  small  ones  yet  untouched.  It  ate  only 
255 


WASPS,    SOCIAL   AND    SOLITARY 

half  of  this  big  one,  however,  and  then  passed  on.  On 
August  second  we  gave  it  two  more  small  crickets,  and 
for  that  day  and  the  one  following  its  good  appetite 
continued,  but  on  August  fourth  it  stopped  eating.  We 
thought  that  its  larval  life  must  be  completed,  and  ex- 
pected to  see  it  spin  its  cocoon,  but  something  was  lack- 
ing which  we  were  too  ignorant  to  supply,  and  on  August 
fifth  it  died.  It  had  eaten  six  small  crickets  and  half  of 
the  large  one,  which  was  equal  to  about  two  more.  Thus 
ended  our  only  acquaintance  with  this  interesting  little 
wasp. 

The  second  week  of  August  furnished  such  good  play 
in  our  garden  that  island  life  was  neglected;  but  one 
brilliant  morning  we  rowed  over  to  the  home  of  Bembex 
and  Philanthus,  hoping  that  something  new  was  in  store 
for  us.  We  were  not  disappointed,  for  as  we  climbed  the 
crest  we  met  a  splendid  Chlorion  cceruleum  dressed  in 
shining  blue,  cricket  in  mouth,  plunging  down  the  hill- 
side through  the  long  grass.  Twenty-five  feet  below, 
she  reached  her  underground  home,  vanished  for  two 
or  three  minutes,  and  then,  coming  to  the  entrance, 
turned  her  head  from  side  to  side  as  though  listening. 
Some  indiscreet  insect  was  chirping  loudly  not  far  away, 
and  before  long  the  wasp  ran  out  into  the  grass,  flew  to 
a  stump,  dropped  to  the  ground,  flew  to  the  top  of  a  tall 
256 


CHLORION    AND    THE    INDISCREET   CRICKET 


THE   ENEMIES    OF   THE    GRASSHOPPER 

weed,  dropped  again,  and  ran  into  a  hole.  A  moment 
later  she  came  out,  dragging  a  very  limp  cricket.  An  ant 
that  crossed  her  path  was  chased  vindictively,  and  then 
the  cricket  was  placed  on  its  back  and  scraped  from 
head  to  foot  four  or  five  times  with  the  mandibles.  She 
then  ran  a  little  farther,  laid  it  down  again,  and  re- 
peated the  operation,  after  which  it  was  taken  into  the 
nest. 

To  find  ourselves  on  the  track  of  a  lively  wasp  at  the 
beginning  of  her  day's  work  was  great  good  luck,  and 
as  Madam  Coeruleum  was  perfectly  fearless  and  did 
her  hunting  on  foot,  instead  of  disconcerting  us  with 
the  long  flights  by  which  many  of  our  wasps  made 
the  chase  hopeless,  we  had  every  chance  to  learn  her 
ways. 

It  was  a  fatal  day  for  the  crickets.  Between  nine 
o'clock  and  one,  sixteen  had  been  packed  away,  enough 
to  provision  three  cells,  as  we  knew  from  former  obser- 
vations. Her  manner  was  brisk  and  energetic,  as  she 
ran  about  poking  her  head  into  every  likely  hole.  At 
one  time  we  saw  her  dislodge  a  cricket  which  tried  to 
escape  by  hiding  under  some  brush.  She  pursued,  there 
was  a  lively  scrimmage,  and  it  was  pulled  out  quite  limp 
and  was  then  held  in  the  mandibles,  back  up,  while  she 
gave  it  a  prolonged  sting  under  the  neck,  after  which 
259 


WASPS,  SOCIAL  AND   SOLITARY 

it  was  carried  home  without  further  manipulation.  At 
another  time  she  paused  in  her  home-coming  to  give  the 
victim  one  long  squeeze  at  the  neck.  The  crickets  were 
placed  in  pockets,  neatly  arranged  on  their  backs  with 
their  heads  inward  and  their  long  legs  projecting  into 
the  main  tunnel.  They  were  alive  when  taken,  but  died 
from  day  to  day  in  the  laboratory,  the  larvae  eating 
them  in  this  state  without  criticism. 

While  we  were  watching  we  noticed  a  much  smaller 
wasp  hovering  about,  and  presently  she  slipped  into 
the  nest.  When  the  owner  returned  and  found  her, 
there  was  a  slight  commotion  in  the  passage-way,  and 
then  the  inquiline  appeared,  shaking  her  wings  in  a 
flippant  manner,  as  though  she  cared  nothing  for  an 
encounter  with  the  Big  Blue.  Instead  of  coming  out 
immediately  as  usual,  coeruleum  stayed  inside  for  twenty- 
five  minutes.  We  should  like  to  think  that  she  was 
occupied  in  finding  and  destroying  the  egg  of  the  para- 
site, but  we  have  no  reason  to  suppose  that  she  could 
recognize  that  menace  to  her  fortunes. 

Coeruleum  lives  in  her  nest  and  enlarges  it  from  day 
to  day  to  fit  her  necessities.  On  going  over  to  the  island 
one  morning  we  found  a  cricket  sleeping  calmly  in  the 
entrance  way,  little  guessing  how  dangerous  was  its  posi- 
tion. It  did  not  budge  until  the  wasp  came  creeping  up 
260 


THE    ENEMIES    OF   THE    GRASSHOPPER 

from  below,  when  it  jumped  away  to  a  place  of  safety. 
Before  the  day's  hunting  began,  a  long  study  of  the 
locality  was  made  on  foot,  tufts  of  grass,  weeds  and 
stones  being  carefully  noted,  and  this  accounts  for  the 
ease  with  which  the  nest  is  afterward  found. 

One  July  afternoon  we  saw  a  little  red  Tachysphex 
tarsata  on  the  Bembex  field  of  the  island.  She  had  a 
very  anxious  air,  and  was  running  about  wildly  and 
rapidly,  holding  a  small  grasshopper  with  the  third 
pair  of  legs.  She  let  it  drop  four  or  five  times,  and  when 
she  picked  it  up  again  she  seemed  to  sting  it,  but  of 
this  we  were  not  quite  certain.  At  last  she  left  it  and 
began  to  rush  about,  investigating  the  Bembex  holes, 
entering  one  of  them  and  perhaps  throwing  out  a  little 
dirt  as  though  she  intended  to  use  it,  and  then  hurrying 
off  to  another.  We  have  no  doubt  that  her  confusion 
was  the  result  of  her  having  lost  track  of  a  hole  that 
she  had  made,  as  was  the  case  with  P.  quinquenotatus 
in  one  of  our  earlier  observations.  The  Pompilus,  after 
a  long  search,  resigned  herself  to  the  necessities  of  the 
case  and  made  a  new  nest ;  but  this  little  wasp  could  not 
adjust  herself  to  a  break  in  the  system  of  her  instinctive 
activities,  and  at  last  deserted  her  prey  and  disappeared. 
We  waited  for  an  hour;  and  then,  as  she  did  not  re- 
turn, we  took  possession  of  the  grasshopper.  It  gave  no 
261 


WASPS,  SOCIAL   AND  SOLITARY 

response  to  stimulation  and  never  revived,  a  very  careful 
examination  later  showing  that  it  was  quite  dead. 

On  the  next  morning  we  again  saw  this  wasp  on  the 
Bembex  field.  She  was  looking  for  a  nesting-place,  and 
when  she  had  selected  one  she  began  to  work ;  the 
weather  was  warm  and  sunny,  so  that  the  Bembecids 
were  in  the  full  swing  of  their  obstreperous  activity,  and 
perhaps  resenting  the  presence  of  the  little  red  wasp,  or 
perhaps  in  a  spirit  of  teasing,  they  kept  snatching  her 
up  and  carrying  her  off  to  a  distance  of  two  or  three 
feet.  She  took  these  interruptions  with  the  most  phi- 
losophic composure,  hurrying  back  to  her  work  as  soon 
as  she  was  released,  without  any  display  of  resentment. 
When  the  nest  was  finished,  she  made  a  careful  locality 
study  both  on  foot  and  on  the  wing  and  then  flew  away. 
In  twenty  minutes  she  came  back,  apparently  to  re- 
fresh her  memory,  for  she  again  made  careful  notes  of 
all  the  points  that  could  help  her  to  identify  the  place. 
She  dug  a  little  more  and  then  departed,  to  return  five 
minutes  later,  on  foot,  with  a  grasshopper.  In  spite  of 
all  the  precautions  she  had  taken,  at  this  exciting  mo- 
ment she  was  unable  to  remember  just  where  her  nest 
was,  and  spent  some  time  in  running  wildly  about,  but 
when  she  did  find  it  she  went  in  without  delay.  We 
caught  her  as  she  came  out,  and  dug  up  the  grasshopper, 
262 


THE    ENEMIES    OF   THE    GRASSHOPPER 

but  found  no  egg,  so  that  she  probably  would  have 
brought  in  a  second  victim  had  we  let  her  go.  The 
tunnel  ran  in  obliquely  for  an  inch  and  a  half,  the 
pocket  at  the  end  being  two  inches  below  the  surface. 

A  few  days  later  we  saw  Larra  quebecensis,  another 
little  grasshopper  wasp,  with  the  same  red  abdomen 
as  tarsata,  going  to  and  fro  about  her  nest,  occasionally 
throwing  out  a  little  sand.  She  ran  about  near  by  all 
through  the  afternoon,  but  was  not  in  a  mood  for  work. 
On  the  next  morning  at  ten  o'clock,  we  found  her  touch- 
ing up  the  nest  a  little,  after  which  she  left  it  open  and 
flew  away.  In  an  hour  she  came  leaping  along  like 
Tachytes,  holding  a  small  grasshopper  in  the  third  legs. 
This  was  placed  inside  the  door  while  she  turned  around, 
and  was  then  pulled  in.  She  came  out  immediately, 
and  in  twenty  minutes  brought  a  second,  and  in  ten 
more  a  third  grasshopper,  staying  within  this  time  for 
some  minutes,  after  which  she  closed  the  nest.  We  took 
out  the  grasshoppers,  one  of  which  bore  an  egg  under- 
neath, in  the  middle,  in  front  of  the  first  pair  of  legs. 
The  grasshoppers  lived  for  five,  six,  and  seven  days,  but 
the  egg  did  not  develop.  We  once  saw  a  quebecensis 
that  had  laid  down  her  grasshopper  while  she  hunted 
for  her  nest.  She  was  moving  in  sinuous  lines  up  and 
down  the  face  of  a  cliff,  with  incredible  rapidity ;  we 
263 


WASPS,    SOCIAL    AND    SOLITARY 

could  not  distinguish  her,  but  could  see  only  a  black 
streak  with  an  occasional  flash  of  crimson.  When  she 
rises  on  her  wings,  too,  she  is  wonderfully  quick,  dis- 
appearing as  if  by  magic,  it  being  quite  impossible  to 
even  guess  at  the  direction  she  is  taking. 


Chapter  XI 

WORKERS    IN    CLAY 

THE  nests  of  Pelopaeus  cceruleus  and  Pelopaeus 
cementarius,  our  two  mud-daubers,  are  common 
under  eaves  and  in  other  sheltered  places,  and  many  a 
country  boy  on  opening  them  has  been  astonished  to 
find  that  they  do  not  contain  wasps,  but  are  crammed 
with  spiders.  Let  them  alone,  however,  and  the  wasps 
will  arrive,  for  somewhere  in  the  mass  is  an  egg;  and 
when  it  hatches  the  spiders  will  serve  as  breakfast,  din- 
ner and  tea  for  the  larva,  until  the  change  from  the 
Arachnida  to  the  Hymenoptera  has  been  accomplished. 
Poor  spiders!  it  is  a  wonder  that  there  are  any  left,  such 
thousands  and  tens  of  thousands  are  destroyed  by  these 
tremendously  energetic  enemies. 

Of  what  is  Pelopaeus  thinking  as,  humming  loudly, 
she  jams  her  paralyzed  and  benumbed  victims  into  her 
little  cylindrical  tubes?  If  only  we  could  get  inside  of 
that  little  head !  If  only  we  could  be  wasps  for  a  day, 
and  then  come  back  and  tell  about  it,  how  much  vain 
speculation  would  be  saved !  We  can  understand  her 
265 


WASPS,    SOCIAL   AND    SOLITARY 

when  she  soars  gayly  into  the  blue,  the  sunshine  flashing 
from  her  brilliant  wings;  we  too  have  felt  the  delight  of 
health  and  freedom.  She  is  still  comprehensible  when, 
at  the  close  of  day,  she  and  her  sisters  quarrel  for  the 
favorite  sleeping-places  among  the  carvings  of  the  porch 
pillars;  but  we  cannot  follow  her  mental  processes 
when,  at  the  moment  of  building,  she  surrenders  herself 
to  the  mysterious  sway  of  instinct,  doing  she  knows  not 
what,  but  doing  it  joyously,  and  preserving  through  it  all 
the  precious  possession  of  her  own  individuality.  Every 
aspect  speaks  of  pleasure  as  these  wasps  gather  at  well 
or  spring,  and,  singing  contentedly,  stand  on  their  heads 
to  gather  their  loads  of  mud.  Briskly  and  gayly  they 
fly  back  and  forth,  pausing  at  the  nest  long  enough  to 
pat  the  soft  building  material  into  shape.  A  single  load 
makes  half  a  ring  at  the  larger  part  of  the  nest  or  a 
whole  one  at  the  bottom ;  and  since  one  dries  before  the 
next  is  put  on,  the  contour  of  each  ring  is  visible  when 
the  tube  is  done,  giving  a  very  artistic  effect.  This  is 
only  accident,  however ;  the  wasp  cares  nothing  about 
the  beauty  of  the  structure,  for  her  next  step  is  to  daub 
the  whole  with  lumps  of  mud,  the  walls  being  thus 
thickened  and  strengthened.  About  forty  loads  are 
necessary  for  each  cell,  and  to  build  and  provision  one 
is  a  good  day's  work. 

266 


WORKERS    IN   CLAY 

It  is  strange  enough  that  with  no  one  to  teach  her 
Pelopaeus  knew  how  to  make  her  cell;  but  now  she  must 
do  her  hunting,  and  it  is  stranger  still  that  she  should 
be  impelled  to  catch  nothing  but  spiders.  How  does 
she  know  a  spider  from  a  fly,  and  why  should  she  pre- 
fer one  to  the  other?  Not  so  unreasonable  as  some 
wasps,  however,  she  demands  nothing  further  than  that 
her  prey  shall  belong  to  this  great  group,  and  passes 
lightly  over  differences  of  species  and  genera.  Her 
powerful  sting  fits  her  to  cope  with  anything  she  may 
meet ;  but  as  the  size  of  the  cell  must  be  taken  into  con- 
sideration, and  the  victim  must  be  carried  home  on  the 
wing,  she  is  on  the  lookout  for  something  not  too  large. 
Here  then  she  ceases  to  be  an  automaton,  and  to  some 
extent  makes  use  of  her  wits. 

How  does  Pelopaeus  seize  her  spider  ?  When  and 
how  many  times  is  it  stung?  Is  the  wound  given  with 
discrimination,  a  certain  point  in  the  ganglion  being 
pricked,  so  that  the  spider  may  be  paralyzed,  but  not 
killed?  Is  there  any  malaxation? 

These  were  important  questions  to  us,  and  we  were 
therefore  greatly  excited  over  our  first  hunt.  One  of 
the  blue  wasps  came  flying  along,  alighted  on  our  cot- 
tage wall,  and  began  her  search,  creeping  into  corners 
and  cracks  and  investigating  cottony  lumps  of  web. 
267 


WASPS,    SOCIAL   AND    SOLITARY 

In  a  few  moments  a  small  Epeira  strix  (the  only  species 
to  be  found  on  the  cottage)  was  dislodged,  and  at  once 
dropped  to  the  floor  of  the  porch.  The  wasp  paid  no 
further  attention  to  it,  but  went  on  with  her  search. 
Three  more  spiders,  one  after  the  other,  were  disturbed 
and  dropped  to  the  floor  without  being  followed.  The 
fifth  one  discovered  was  a  little  larger  than  the  others, 
and  was  seized  by  the  jaws  and  first  legs  of  the  wasp 
before  it  had  time  to  escape.  It  was  then  rolled  into  a 
ball,  or  at  least  so  it  appeared,  and  stung,  then  rolled 
a  little  more  and  stung  again,  and  then  carried  off.  We 
had  scarcely  drawn  breath  after  this  performance 
when  a  second  wasp  appeared.  This  one  dislodged  two 
spiders,  and  then  caught  a  third,  which  was  seized  and 
stung  without  any  rolling,  and  then  instantly  borne 
away.  A  third  wasp  seized  the  first  spider  that  she 
found,  and  started  on  her  flight  at  the  same  moment, 
stinging  it  on  the  wing. 

So  the  game  went  on,  while  we  waxed  warm  with  the 
excitement  and  fascination  of  the  chase.  As  the  hours 
went  by  some  of  the  yellow  mud-daubers  appeared, 
adding  to  the  interest  of  the  scene,  although  we  could 
not  see  that  their  method  differed  in  the  least  from  that 
of  coeruleus. 

Rarely  did  they  succeed  in  catching  a  spider  until 
268 


WORKERS    IN    CLAY 

they  had  dislodged  two  or  three.  Sometimes  the  spiders 
were  followed  as  they  dropped,  and  were  caught  on  the 
floor,  but  oftener  the  wasp  let  them  escape  and  continued 
her  search  on  the  wall.  At  the  moment  of  capture  we 
could  see  that -she  bent  her  abdomen  under  and  in- 
flicted a  sting,  but  although  we  concentrated  our  atten- 
tion on  the  point  we  could  not  be  sure  as  to  just  what 
part  was  touched.  It  is  our  impression  that  this  first 
sting  was  given  anywhere,  at  random,  with  the  object 
of  producing  a  condition  of  temporary  quiet  in  the 
victim,  so  that  the  next  part  of  the  operation  could  be 
carried  on  with  deliberation. 

The  second  step  in  the  procedure  was  commonly  for 
the  wasp  to  alight  upon  some  neighboring  object,  usu- 
ally the  branch  of  a  bush  or  tree,  and  sting  the  spider 
a  second  time,  being  evidently  in  no  haste ;  but  the 
difficulty  of  following  her  as  she  flew,  and  her  habit 
of  alighting  above  our  range  of  vision,  made  it  almost 
impossible  to  see  just  what  she  did.  She  certainly  re- 
mained on  the  branch  for  some  moments,  either  resting 
quietly  or  rolling  the  spider  around  and  around,  and 
had  every  opportunity  to  sting  it  as  carefully  as  she 
wished;  but  we  afterward  found  that  she  followed  no 
exact  method,  since  two  thirds  of  the  spiders  were 
killed  at  the  moment  of  capture,  and  most  of  the  others 
269 


WASPS,    SOCIAL   AND    SOLITARY 

died  within  a  week,  while  a  few  lived  for  thirty-five  or 
forty  days.  In  this  study  we  opened  five  hundred  and 
seventy-three  cells  and  handled  over  two  thousand  spi- 
ders, watching  over  them  from  day  to  day  with  a  mag- 
nifying glass,  that  no  sign  of  life  might  be  neglected. 

When  Pelopaeus  has  filled  her  cell,  she  seals  it  up  and 
makes  another  close  to  it,  clusters  of  from  six  to  twenty 
being  found  in  one  spot.  Any  especially  desirable  place 
is  used  by  great  numbers;  and  they  make  a  lively  scene, 
working  eagerly  at  their  nests,  dashing  off  for  more  mud 
or  bringing  in  their  victims.  All  animated  by  the  same 
compelling  instinct,  they  are  still  individuals,  and  the 
character  of  each  enters  into  her  work.  One  picks  up 
the  first  spider  she  sees,  no  matter  how  tiny  it  may 
be,  and  makes  twenty-five  or  thirty  journeys  before 
her  cell  is  filled,  while  another  seems  to  have  a  calcu- 
lating turn  of  mind,  using  four  or  five  big  spiders  in- 
stead of  a  quantity  of  small  ones.  Has  she  made  a  note 
of  the  calibre  of  her  cell,  and  determined  to  save  herself 
trouble  by  looking  farther  and  selecting  the  largest 
ones  that  will  go  in? 

Most  of  them  place  their  cells  vertically;  but  a  few 
prefer  the  horizontal  position,  while  still  others,  unde- 
cided as  to  the  matter  of  direction,  make  clusters  in 
which  some  are  horizontal  and  others  upright.  Occa- 
270 


WORKERS   IN   CLAY 

sionally  there  is  a  remarkable  innovation  in  building- 
material,  as  where  in  a  group  of  fifteen,  four  cells  in  the 
centre  were  constructed  of  pure  white  plaster,  forming 
a  striking  contrast  to  the  surrounding  mud  color.  One 
wasp  built  an  entire  cluster  after  an  original  fashion, 
following  the  beaten  track 
until  the  cell  was  completed, 
and  even  bringing  mud 
enough  to  daub  it  over,  as 
her  sisters  were  doing,  but 
sticking  it  all  in  one  spot,  so 

that    when    the    group    was        HORIZONTAL  CELLS  OF  THE 

,  .  ,  ,  MUD-DAUBER 

complete     irregular     lumps 

were  attached  here  and  there,  leaving  visible  the  elegant 
architecture  of  the  individual  cells.  Did  she  think  they 
were  too  pretty  to  spoil  ?  or  was  she  merely  one  of  those 
radical  spirits  that  rebel  against  conventionality  and 
demand  change  for  the  sake  of  change?  It  is  these 
variations  that  furnish  Natural  Selection  with  its  ma- 
terials; but  rigid  as  may  be  the  rules  regarding  the 
non-survival  of  the  unfit,  we  find  that  the  race  of  Pelo- 
pseus  still  produces  many  absent-minded  wasps,  that 
after  spending  hours  in  carefully  constructing  their 
nests,  seal  them  up  empty,  forgetting  to  put  in  the 
spiders  or  to  lay  the  egg. 

271 


WASPS,   SOCIAL   AND    SOLITARY 

When  a  cell  is  sealed,  the  mother  wasp  ceases  to  take 
an  interest  in  it,  but  she  has  done  all  that  is  necessary. 
In  two  or  three  days  the  egg  hatches,  after  which  the 
larva  spends  ten  or  fifteen  days  in  eating,  and  then 
spins  its  cocoon.  Here  it  remains,  perhaps  for  only  a 
few  weeks,  —  for  there  are  two  or  three  generations  in 
one  season,  —  or  perhaps  through  the  long  months  of 
winter. 

Fabre  gives  a  most  entertaining  account  of  a  French 
species  of  Pelopaeus  which  nests  in  the  wide-mouthed 
chimneys  of  the  peasant.  Undisturbed  by  the  steam 
of  washing  day  or  the  bustle  of  dinner-getting,  the  wasp 
enters  the  open  door,  passes  unconcerned  among  the 
human  inhabitants,  and  makes  her  cells  against  the 
smoky  bricks,  out  of  reach  of  the  flames.  This  species 
kills  her  prey  at  the  moment  of  capture,  by  which  act 
she  falls  in  the  estimation  of  Fabre,  who  respects  a 
wasp  in  proportion  to  the  nicety  with  which  she  delivers 
her  sting.  He  says,  however,  that  at  least  she  follows 
a  logical  method  in  turning  to  account  these  spiders, 
menaced  with  early  decay.  In  the  first  place  the  prey  is 
multiplied  in  each  cell.  The  piece  actually  attacked  by 
the  larva  is  soon  a  disorganized  mass,  likely  to  decay 
speedily ;  but  it  is  small  and  is  consumed  before  decom- 
position can  advance,  for  when  a  larva  once  attacks  a 
272 


WORKERS    IN    CLAY 

spider  it  does  not  leave  it  for  another.  The  others  then 
remain  intact,  which  is  enough  to  keep  them  fresh  during 
the  short  period  of  larval  life.  When,  on  the  contrary, 
the  prey  consists  of  a  single  large  piece,  it  is  necessary 
that  the  organic  life  should  be  maintained,  and  a  special 
art  must  also  be  observed  in  eating  it.  It  is  well  then 
that  Pelopaeus  is  inspired  to  take  numerous  small  pieces. 
The  egg,  moreover,  is  always  placed  on  the  first  spider 
brought  in,  whether  the  storing  of  the  nest  is  completed 
within  a  few  hours,  or  whether,  as  in  some  cases,  it 
occupies  several  days;  and  this  M.  Fabre  considers  a 
very  happy  arrangement. 

The  French  Pelopaei  differ  from  ours  at  nearly  every 
point.  Ours  kill  only  about  two  thirds  of  their  victims, 
many  of  the  others  being  paralyzed  so  perfectly  that 
they  live  for  two  or  three  weeks.  Again,  ours,  instead 
of  placing  the  egg  upon  the  first  spider,  almost  invariably 
lay  it  upon  the  last  one  brought  in.  Another  point  of 
difference  is  that  our  larvae  frequently  start  in  by  eating 
up  the  soft  abdomens,  like  children  who  first  devour 
the  plums  in  their  pudding,  returning  later  to  the  tough 
parts  that  are  left,  a  rash  and  reprehensible  course  of 
action  of  which  their  better-taught  French  cousins  are 
never  guilty.  When  one  comes  to  compare  the  two  sets 
of  facts  furnished  by  the  two  groups  of  species,  the 
273 


WASPS,   SOCIAL   AND   SOLITARY 

deductions  which  Fabre  has  drawn  as  to  the  importance 
of  the  instincts  of  the  French  group  are  seen  to  be  un- 
founded. The  American  species  violate  nearly  every 
principle  which  he  considers  necessary  to  their  existence, 
and  yet  they  flourish  and  multiply.  For  our  part  we 
find  nothing  in  the  actions  of  Pelopaeus  that  needs  to 
be  explained  —  nothing  that  is  not  well  adapted  to  the 
conditions  under  which  each  species  works.  The  mea- 
sure of  praise  or  blame  which  we  mete  out  to  these 
depredators  is  merely  a  way  of  saying  whether  we  would 
or  would  not  follow  their  methods  in  provisioning  our 
houses  and  rearing  our  children.  Perhaps  we  would 
always  use  large  spiders  and  would  always  have  them 
fresh;  but  it  is  evident  that  tastes  differ,  and  the  matter 
is  so  purely  a  subjective  affair  that  it  will  have  to  go 
unsettled.  In  any  event,  whether  her  victims  be  strong 
or  feeble,  old  or  young,  big  or  little,  fresh  or  dry,  they 
certainly  serve  admirably  in  enabling  Pelopaeus  to  rear 
brood  after  brood,  and  to  people  the  different  parts  of 
the  earth  with  abundant  representatives  of  her  kind. 


Chapter  XII 

SENSE    OF    DIRECTION 

WE  once  made  a  number  of  experiments  to  dis- 
cover in  what  way  the  social  wasps  came  back 
to  the  nest  on  returning  from  their  hunting  expeditions. 
Were  they  endowed  with  some  innate  power  which 
made  memory  of  places  unnecessary,  and  enabled  them 
to  fly  in  a  straight  line  to  any  point  they  wished  to  reach, 
or  did  their  return  depend  upon  the  more  common- 
place method  of  remembering  the  appearance  of  the 
countryside  ? 

One  morning  at  half  past  eight,  we  placed  a  wasp 
cage  over  the  opening  of  a  yellow- jacket  hole  that  had 
been  closed  since  the  night  before,  and  caught  fifty- 
five  workers,  after  which  the  nest  was  again  closed,  one 
of  us  taking  the  cage  out  on  to  the  lake,  while  the  other 
remained  to  watch  for  their  return. 

At  seven  minutes  before  nine,  twenty  of  the  wasps 
were  liberated  an  eighth  of  a  mile  from  shore  near  the 
end  of  the  island.  All,  without  exception,  flew  toward 
275 


WASPS,    SOCIAL   AND    SOLITARY 

the  island  and  away  from  the  nest.  Whether  they  set- 
tled could  not  be  determined.  The  boat  was  then 
moved  an  eighth  of  a  mile  beyond  the  island  to  the 
north,  where,  at  ten  minutes  after  nine,  the  remaining 
wasps  were  set  free.  They  seemed  a  good  deal  con- 
fused, and  flew  in  all  directions.  Many  returned  to  the 
boat  and  alighted,  but  soon  flew  away  again.  Two  that 
settled  on  the  boat  were  knocked  into  the  water;  but 
they  instantly  rose  and  circled  up  into  the  air  until  out 
of  sight. 

Of  the  fifty-five  wasps  that  we  set  free,  thirty- nine 
returned  to  the  nest  by  ten  o'clock,  five  of  them  belong- 
ing to  the  lot  that  flew  to  the  island,  since  they  soon 
found  their  bearings  and  came  directly  home,  reaching 
the  nest  before  the  wasps  of  the  second  lot  were  liberated. 

Of  the  thirty-five  wasps  that  were  set  free  at  the  sec- 
ond point,  at  least  twenty  started  in  wrong  directions. 
Adding  these  to  the  first  twenty,  we  have  left  only  fif- 
teen that  appeared  to  know  where  to  look  for  their 
home,  and  yet  thirty-nine  reached  the  nest  in  a  little 
more  than  an  hour  from  the  time  the  first  wasps  were 
set  free. 

On  another  morning  we  caught  thirty-eight  workers 
and  took  them  to  a  boat-house  on  the  shore  of  the  lake, 
in  the  second  story  of  which  was  a  large  room  with  two 
276 


SENSE    OF    DIRECTION 

good- sized  windows;  one  looked  west  over  the  lake  and 
away  from  the  nest,  the  other  east  toward  the  nest,  and 
both  were  wide  open.  The  west  window  was  the  brighter, 
but  the  other  was  light,  the  sun  being  on  that  side  of  the 
house. 

We  placed  the  cage  in  the  middle  of  this  room  and 
opened  the  door,  stationing  ourselves  well  to  one  side 
so  as  not  to  interfere  with  the  movements  of  the  wasps. 
They  came  out  very  naturally,  pausing  a  moment  before 
flying,  and  followed  each  other  so  slowly  that  we  could 
easily  see  which  window  they  went  out  by.  Twenty- 
two  flew  through  the  west  window  away  from  the  nest, 
and  sixteen  through  the  east  toward  the  nest. 

At  another  time  we  took  fourteen  wasps  from  the 
nest  of  a  different  species  and  carried  them  seventy- 
three  yards  to  the  southeast.  The  cage  was  opened  so 
that  they  could  fly  out  in  any  direction  they  chose,  and 
they  all  started  in  a  straight  line  for  the  nest.  Later  on 
the  same  day,  we  took  forty-five  from  this  nest,  and  set 
them  free  one  hundred  and  seventy-six  yards  to  the 
south.  Seven  flew  north  toward  the  nest,  twenty-one 
south,  eight  west,  and  seven  east,  while  the  other  two 
circled  around  as  they  rose  higher  and  higher,  until 
they  were  lost  to  view.  None  in  this  experiment  returned 
to  take  a  fresh  start. 

277 


WASPS,    SOCIAL   AND    SOLITARY 

Again,  we  took  twenty-three  wasps  three  hundred 
yards  southeast  of  the  nest  and  liberated  them  in  an 
open  field  ;  thirteen  flew  east  or  south  away  from  the 
nest,  seven  west  or  northwest  toward  the  nest,  and  four 
returned  to  the  starting-place  and  seemed  unwilling  to 
venture  out  again. 

These  observations  show  that  the  two  species  of 
wasps  with  which  we  experimented  have  no  sense  of 
direction  in  the  form  of  a  mysterious  additional  sense, 
nor  yet  in  the  form  of  a  power  by  which  they  keep  a 
register  of  the  turns  and  changes  in  a  journey  and  are 
thus  able  to  retrace  their  way.  Our  cage  was  of  wire, 
and  so  open  that  they  could  see  all  about,  as  we  carried 
them  from  place  to  place;  yet  when  they  flew  out,  they 
most  frequently  started  in  a  wrong  direction  and  toward 
a  point  that  we  had  not  passed.  In  many  instances, 
however,  these  wasps  returned  to  the  nest,  and  it  seems 
highly  probable  that  as  they  rose  higher  and  higher  into 
the  air,  circling  as  they  went,  they  discovered  some  lofty 
treetop  or  other  object  that  had  before  served  them  as  a 
landmark,  and  that  in  this  way  they  were  able  to  make 
their  way  home.  Bee-keepers  know  that  if  young 
workers  which,  in  strong  hives,  pass  the  first  ten  or 
fifteen  days  of  their  lives  in  feeding  the  larvae  without 
going  abroad,  are  taken  out  and  set  free  only  a  short 
278 


SENSE    OF    DIRECTION 

distance  from  home,  they  are  unable  to  find  their  way 
back,  and  perish,  while  those  that  have  passed  beyond 
the  nursing  stage  and  have  begun  to  do  outside  work 
may  be  carried  long  distances  away  and  still  readily 
regain  the  nest. 

With  the  solitary  wasps  we  attacked  the  problem 
from  the  other  end.  We  observed  what  the  social  wasps 
did  in  attempting  to  return  to  the  nest ;  with  the  soli- 
taries, we  watched  them  when,  after  making  the  nest, 
they  prepared  to  leave  it  to  go  out  into  the  fields  or 
woods  in  search  of  food  or  prey,  thinking  that  the  pro- 
cedure of  different  species  under  these  circumstances 
would  afford  a  clue  to  the  faculty  upon  which  they  de- 
pended to  find  their  way  about.  If  they  were  furnished 
with  an  innate  sense  of  direction  they  would  not  need 
to  make  a  study  of  the  locality  of  the  nest  in  order  to 
find  the  way  back,  but  if  they  were  without  this  sense 
it  would  be  only  common  prudence  to  take  a  good 
account  of  their  bearings  before  going  far  afield. 

The  sight  of  a  bee  or  a  wasp  returning  to  its  home 
from  some  far  distant  spot,  without  hesitation  or  un- 
certainty, is  indeed  marvelous.  When  we  saw  our  first 
Ammophila  perform  this  feat  we  were  filled  with  won- 
der. How  was  it  possible  for  her  to  hunt  for  hours,  in 
all  directions,  far  and  wide,  and  then  return  in  a  direct 
279 


WASPS,    SOCIAL   AND    SOLITARY 

line  to  a  nest  which  had  been  so  carefully  covered  over 
that  every  trace  of  its  existence  was  obliterated  ? 

To  say  that  she  is  a  creature  of  instinct,  however,  is 
not  quite  fair  to  her  ladyship's  intelligence,  as  a  better 
acquaintance  with  her  would  prove.  In  reading  much 
popular  natural  history  one  might  suppose  that  the  in- 
sects seen  flying  about  on  a  summer's  day  were  a  part  of 
some  great  throng  which  is  ever  moving  onward,  those 
that  are  here  to-day  being  replaced  by  a  new  set  on  the 
morrow.  Except  during  certain  seasons  the  exact  op- 
posite of  this  is  true.  The  flying  things  about  us  abide 
in  the  same  locality  and  are  the  inhabitants  of  a  fairly 
restricted  area.  The  garden  in  which  we  worked  was, 
to  a  large  extent,  the  home  of  a  limited  number  of  cer- 
tain species  of  wasps  that  had  resided  there  from  birth, 
or  having  found  the  place  accidentally,  had  settled  there 
permanently.  To  make  this  matter  clear  let  us  suppose 
the  case  of  an  individual  of  A.  urnaria.  In  June  she 
spent  her  time  in  sipping  nectar  from  the  onion  flowers 
or  from  the  sorrel  that  grew  on  the  border  of  the  garden. 
In  July  came  the  days  of  her  courtship  and  honey- 
moon, and  these  too  were  passed  in  going  from  flower  to 
flower,  from  one  part  of  the  garden  to  another.  Many  a 
day  we  have  followed  her  when  she  flew  from  blossom 
to  blossom  along  a  row  of  bean  plants,  turning,  when 
280 


SENSE    OF    DIRECTION 

she  reached  the  end,  and  wending  her  way  leisurely 
back  along  the  next  row.  Then  comes  a  day  when  we 
see  her  running  over  the  ground  and  looking  carefully 
under  the  weeds  for  a  good  nesting-place.  At  last  a  spot 
is  selected  and  she  begins  to  dig ;  but  two  or  three  times 
before  the  work  is  completed  she  goes  away  for  a  short 
flight.  When  it  is  done,  and  covered  over,  she  flies 
away,  but  returns  again  and  again  within  the  next  few 
hours,  to  look  at  the  spot  and,  perhaps,  to  make  some 
little  alteration  in  her  arrangements.  From  this  time  on, 
until  the  caterpillars  are  stored  and  the  egg  laid,  she 
visits  her  nest  several  times  a  day,  so  that  she  becomes 
perfectly  familiar  with  the  neighborhood,  and  it  is  not 
surprising,  after  all,  that  she  is  able  to  carry  her  prey 
from  any  point  in  her  territory  in  a  nearly  direct  line 
to  her  hole  —  we  say  nearly  direct,  for  there  was  almost 
invariably  some  slight  mistake  in  the  direction  which 
made  a  little  looking  about  necessary  before  the  exact 
spot  was  found. 

After  days  passed  in  flying  about  the  garden  —  going 
up  Bean  Street  and  down  Onion  Avenue,  time  and 
time  again  —  one  would  think  that  any  formal  study 
of  the  precise  locality  of  a  nest  might  be  omitted;  but 
it  was  not  so  with  our  wasps.  They  made  repeated 
and  detailed  studies  of  the  surroundings  of  their  nests. 
281 


WASPS,    SOCIAL   AND    SOLITARY 

Moreover,  when  their  prey  was  laid  down  for  a  moment 
on  the  way  home,  they  felt  the  necessity  of  noting  the 
place  carefully  before  leaving  it. 

Of  the  species  that  catch  their  prey  before  making 
the  nest  we  have  good  examples  in  Pompilus  quinqueno- 
tatus,  the  tornado  wasp,  and  fuscipennis,  the  Pompilus 
with  the  red  girdle. 

The  tornado  wasp  may  make  her  nest  anywhere  from 
one  to  ten  feet  from  the  spot  on  which  she  has  deposited 
her  spider,  while  fuscipennis  never  goes  more  than  four- 
teen inches  away.  During  the  process  of  excavation 
both  of  these  wasps  pay  several  visits  to  the  spider,  and 
frequently  they  have  difficulty  in  finding  it.  As  an  ex- 
ample of  this  kind  of  trouble  we  give  a  diagram  of  the 
course  followed  by  an  individual  of  fuscipennis  after 
she  had  finished  her  nest,  in  trying  to  -find  her  spider 
and  in  bringing  it  home.  This  and  the  other  similar 
diagrams  that  are  given  are  reductions  of  large  tracings 
that  were  made  on  the  spot.  Although  not  absolutely 
correct  they  are  exact  enough  for  all  practical  purposes, 
since  wherever  there  is  an  error  it  is  necessarily  in  the 
direction  of  making  the  path  pursued  by  the  wasp 
appear  shorter  and  less  complex  than  it  really  was. 
The  individual  in  question  had  placed  her  spider  on  a 
cucumber  vine  which  lay  on  the  ground,  not  hidden  by 
282 


SENSE    OF    DIRECTION 

leaves,  but  fully  exposed  to  view.    The  nest  was  only 
eight  inches  away,  but  when  it  was  finished  and  the 


COURSE  FOLLOWED  BY  POMPILUS  FUSCIPEN- 
NIS  IN  FINDING  HER  SPIDER  AND  IN 
RETRACING  HER  STEPS  TO  THE  NEST  1 

wasp  went  to  bring  the  spider,  she  found  it  only  after 
a  search  of  three  minutes ;  and  then  when  she  went 

1  The  nest  being  completed,  the  wasp  went  skimming  over  the 
ground  as  indicated  by  the  line,  until  the  spider,  which  had  previ- 
ously been  stung  and  placed  upon  a  leaf,  was  found.  She  then 
dragged  it  some  distance  beyond  the  nest  to  the  point  2,  from  which 
place  she  took  it  to  the  nest. 

283 


WASPS,    SOCIAL   AND    SOLITARY 

back  to  the  nest  she  at  first  passed  to  one  side  and  went 
some  inches  beyond,  so  that  she  had  to  retrace  her 
steps. 

Marchal  notes  that  some  wasps  are  very  unskillful 
in  finding  their  way  about,  showing  by  their  errors  and 
hesitations  not  only  that  they  have  no  sense  of  direction, 
but  that  they  are  badly  served  by  their  memory  and  by 
what  senses  they  have.  He  draws  this  conclusion  from 
his  own  observations,  one  of  which  had  for  its  subject 
Pompilus  seriaceus,  which  nests,  conveniently  for  him, 
in  the  walls  of  the  rustic  summer-house  which  he  uses 
for  a  laboratory.  A  wasp  of  this  species,  having  caught 
her  spider,  had  a  most  wearisome  experience  in  getting  it 
to  the  nest,  which  had  been  previously  excavated  near 
the  ground.  She  first  carried  it  straight  up,  not  only 
passing  the  opening,  but  going  to  the  very  top  of  the 
wall.  Realizing  that  she  had  gone  wrong,  she  laid  it 
down,  and  after  a  prolonged  hunt  up  and  down,  to 
the  right  and  to  the  left,  found  the  nest ;  but  on  leav- 
ing it  again  to  go  for  the  spider,  she  started  in  exactly 
the  wrong  direction,  down  instead  of  up;  and  not  until 
forty  minutes  had  been  spent  in  searching  alternately 
for  spider  and  for  nest  did  she  finally  bring  the  two 
together. 

The  best  evidence  that  wasps  depend  upon  a  know- 
284 


SENSE    OF    DIRECTION 

ledge  of  the  place  in  returning  to  their  nests  is  given  by 
the  pains  they  take  to  acquire  that  knowledge.  When 
Sphex  ichneumonea  was  ready  to  dig  her  nest,  she  had 
great  difficulty  in  finding  a  place  that  suited  her.  Many 
a  spot  was  merely  looked  at  and  passed  by,  while  others 
that  seemed  more  attractive  were  left  after  they  had 
been  excavated  for  a  little  way.  At  last,  the  nest  dug, 
she  was  ready  to  go  out  and  seek  for  her  store  of  pro- 
visions; and  now  came  a  most  thorough  and  systematic 
study  of  the  surroundings.  The  nests  that  had  been 
partly  made  and  then  deserted  had  been  left  without 
any  circling.  Evidently  she  was  conscious  of  the  differ- 
ence and  meant,  now,  to  take  all  necessary  precautions 
against  losing  her  way.  She  flew  in  and  out  among  the 
plants,  first  in  narrow  circles  near  the  surface  of  the 
ground,  and  now  in  wider  and  wider  ones  as  she  rose 
higher  in  the  air,  until  at  last  she  took  a  straight  line  and 
disappeared  in  the  distance.  Very  often,  after  one 
thorough  study  of  the  topography  of  her  home  has  been 
made,  a  wasp  goes  away  a  second  time  with  much  less 
circling  or  with  none  at  all. 

If  the  examination  of  the  objects  about  the  nest 
makes  no  impression  upon  the  wasp,  or  if  it  is  not  re- 
membered, she  ought  not  to  be  inconvenienced  nor 
thrown  off  her  track  when  weeds  and  stones  are  removed 


WASPS,   SOCIAL   AND   SOLITARY 

and  the  surface  of  the  ground  is  smoothed  over;  but 
this  is  just  what  happens.  Aporus  fasciatus  entirely 
lost  her  way  when  we  broke  off  the  leaf  that  covered 
her  nest,  but  found  it,  without  trouble,  when  the  missing 
object  was  replaced.  All  of  the  species  of  Cerceris  were 
extremely  annoyed  if  we  placed  any  new  object  near 
their  nesting-places.  One  Ammophila  refused  to  make 
use  of  her  burrow  after  we  had  drawn  some  deep  lines 
in  the  dust  before  it.  The  same  annoyance  is  exhibited 
when  there  is  any  change  made  near  the  spot  upon 
which  the  prey  of  the  wasp,  whatever  it  may  be,  is  de- 
posited temporarily.  We  learned  from  experience  how 
important  it  was  not  to  disarrange  the  grass  or  plants 
on  such  occasions.  The  wasps  are  in  many  cases  so 
prudent  as  to  conceal  their  booty  among  the  leaves ;  and 
this  made  it  very  inconvenient  to  keep  our  eyes  upon 
the  captured  prey,  as  was  quite  necessary  if  we  wished 
to  follow  it  on  its  travels.  To  avoid  the  discomfort  of 
lying  on  the  ground  or  of  twisting  the  neck  at  some  im- 
possible angle  for  half  an  hour  at  a  time,  we  sometimes 
gently  moved  the  intercepting  objects  to  one  side  ;  but 
even  such  a  slight  change  cost  us  dear  in  time  and  pa- 
tience, as  it  threw  the  wasp  out  of  her  bearings  and  made 
it  difficult  for  her  to  recover  her  treasure.  We  recall 
one  exceedingly  warm  day  in  September  when  we  were 
286 


SENSE    OF    DIRECTION 

delayed  in  this  way  for  forty  minutes,  when  she  would 
have  seized  the  spider  and  gone  on  her  way  without  a 
pause  had  we  not  interfered. 

Very  often  the  wind  would  shake  the  plant  so  that 
the  spider  or  caterpillar  would  fall  to  the  ground.  Under 
these  circumstances  the  wasp  was  not  at  all  disconcerted, 
but,  on  not  finding  her  prey  where  she  had  left  it,  dropped 
at  once  to  where  it  was  lying.  This  is  probably  only  an 
extension  of  their  ordinary  habits.  A  wasp  that  takes 
spiders  learns  to  follow  them  as  they  drop  from  the  web 
on  being  disturbed.  In  this  they  are  evidently  guided 
by  sight,  but  perhaps  they  are  also  aided  by  the  sense 
of  smell  under  other  conditions,  —  to  the  extent,  at  least, 
of  recognizing  the  place  upon  which  their  prey  has  lain. 
With  so  much  to  build  upon,  it  is  easy  to  see  how  natural 
selection  may  have  perfected  the  habit.  We  are  delaying 
a  long  time  over  details,  but  we  feel  that  to  invoke  an 
unknown  sense  is  permissible  only  after  a  careful  study 
of  the  daily  life  of  the  animals  in  question  has  left  the 
problem  unsolved. 

Among  the  wasps  that  first  make  the  nest  and  then 
provision  the  larder,  Astata  bicolor  is  one  of  the  most 
interesting.  She  makes  a  permanent  abiding-place, 
and  probably  uses  it  until  all  of  her  eggs  are  laid.  It 
is  evident  that  since  she  comes  and  goes  many  times 
287 


WASPS,    SOCIAL    AND    SOLITARY 


during  the  several  weeks  of  her  occupation,  she  does 
not  need  to  make  a  prolonged  study  of  the  environment 
at  every  departure.  Her  first  survey,  just  after  the  nest 
is  completed,  is  most  thorough;  and,  as  a  usual  thing, 
when  she  first  comes  out  on  each  succeeding  morning, 
she  reviews  the  situation  more  or  less  carefully.  Indi- 
viduals differ  in  this  respect,  however,  some  studying 
their  local  habitat  much  more  than  others.  In  this  as 

well  as  in  all  other  mat- 
ters our  observations 
are  in  complete  accord 
with  those  of  Sir  John 
Lubbock,  who  says: 
"Indeed,  many  of  my 
experiences  seem  to 
show  not  only  a  differ- 
ence of  character  in  the 

LOCALITY  STUDY  OP  ASTATA  B1COLOR  1        ^^  ^.^  Q£  ^ 

but  that  even  within  the  limits  of  the  same  species 

1  The  wasp  flew  from  nest  to  i, paused  a  moment,  then  flew  back; 
then  to  2,  paused  and  flew  back ;  then  to  3,  paused,  then  to  4,  paused 
and  flew  back  to  nest ;  flew  to  4,  5,  6,  7,  8,  and  9,  pausing  at  each  spot, 
and  flew  back  to  nest  along  10;  flew,  successively,  along  n,  12  and 
13,  resting  at  the  spots  designated;  from  13  she  circled  around  nest 
in  direction  of  arrow  points  and  departed. 
288 


SENSE   OF   DIRECTION 


there  are  individual  differences  between  ants,  just  as 
between  men."  1 

This  little  bug-hunting  Astata  bicolor  made  her 
study  in  a  different  way  from  Sphex  ichneumonea.  She 
first  flew  from  the  nest 
to  a  spot  near  by  and 
settled  there,  returning, 
after  a  moment,  to  the 
nest,  or  else  flying  to 
another  resting-place. 
After  pausing  in  a 
number  of  places  (in 
the  case  of  the  one  fol- 
lowed in  the  diagram, 
thirteen),  she  finished 
by  a  rapid  zigzag  flight. 
Another  wasp  of  this 
genus,  unicolor,  differed  from  bicolor  in  not  returning 
to  the  nest  from  the  different  resting-places,  and  in 

1  Ants,  Bees,  and  Wasps,  p.  95. 

2  The   continuous  line   shows  the   course  walked   over  by  the 
wasp,  the  short  marks  at  right  angles  representing  resting-places; 
the  broken  line  indicates  flight.     Line  i  shows  the  first  study,  lead- 
ing back  to  the  nest,  and  line  2  the  second,  ending  in  flight  and 
departure. 

289 


LOCALITY  STUDY  OF  ASTATA   UNI- 
COLOR 2 


WASPS,    SOCIAL   AND    SOLITARY 

walking  from  one  to  another  of  them  instead  of  flying, 
although  the  last  part  of  the  study  was  made  on  the 
wing. 

Cerceris  deserta  was  one  of  the  wasps  that  objected 
strongly  to  our  presence,  and  she  also  made  a  great  deal 
of  fuss  about  leaving  her  nest.  Nearly  all  the  species 
circle  before  leaving  a  spot  to  which  they  intend  to 
return,  but  deserta  begins  her  flight  with  a  series  of 


SECOND    LOCALITY    STUDY    OF    A.    UNICOLOR  1 

short  zigzags  in  the  form  of  a  half  circle  on  one  side 
of  the  nest.  C.  nigrescens,  too,  begins  with  semicircles, 
while  C.  clypeata  flies  entirely  around  and  around  the 

1  The  continuous  line  shows  the  course  walked  over  by  the  wasp  ; 
the  short  marks  at  a  right  angle  indicate  resting-places  ;  the  broken 
line  indicates  flight. 

290 


SENSE    OF    DIRECTION 

opening.  The  contrast  between  the  deliberate  move- 
ments of  Astata  and  the  rapid  flight  of  Cerceris  is  very 
striking. 

We  have  now  given  a  sufficient  number  of  instances, 
from  widely  separated  genera,  to  show  the  care  that  is 
taken  by  wasps  to  acquaint  themselves  with  the  sur- 
roundings of  their  nests.  It  has  also  been  shown  that 
in  spite  of  all  this  care  they  frequently  have  trouble  in 
finding  their  way  about.  All  these  facts  have  led  us  to 
conclude  that  wasps  are  guided  in  their  movements  by 
their  memory  of  localities.  They  go  from  place  to  place 
quite  readily  because  they  are  familiar  with  the  details 
of  the  landscape  in  the  district  they  inhabit.  Fair  eye- 
sight and  a  moderately  good  memory  on  their  part  are 
all  that  need  be  assumed  in  this  simple  explanation  of 
the  problem. 


Chapter   XIII 

INSTINCT    AND    INTELLIGENCE 

OUR  study  of  the  activities  of  wasps  has  satisfied 
us  that  it  is  impracticable  to  classify  them  in  any 
simple  way.  The  old  notion  that  the  acts  of  bees,  wasps, 
and  ants  were  all  varying  forms  of  instinct  is  no  longer 
tenable,  and  must  give  way  to  a  more  philosophical 
view.  It  would  appear  to  be  quite  certain  that  there 
are  not  only  instinctive  acts  but  acts  of  intelligence  as 
well,  and  a  third  variety  also  —  acts  that  are  probably 
due  to  imitation,  although  whether  much  or  little  in- 
telligence accompanies  this  imitation  is  admittedly  dif- 
ficult to  determine.  Again,  acts  that  are  instinctive  in 
one  species  may  be  intelligent  in  another,  and  we  may 
even  assert  that  there  is  a  considerable  variation  in 
the  amount  of  intelligence  displayed  by  different  in- 
dividuals of  the  same  species.  We  have  met  with 
such  difficulty  in  our  attempts  to  arrange  the  activities 
of  wasps  in  different  groups  that  we  are  forced  to  the 
conclusion  that  any  scheme  of  classification  is  merely 
a  convenience,  useful  for  purposes  of  study  or  generali- 
292 


INSTINCT   AND    INTELLIGENCE 

zation,  but  not  to  be  taken  for  an  absolutely  true  ex- 
pression of  all  the  facts.  This  kind  of  perplexity  is  well 
understood  and  allowed  for  in  all  morphological  work, 
but  it  has  never  been  fully  realized  in  the  study  of  habits. 
The  explanation  is  not  far  to  seek.  The  habits  of  but 
few  animals  have  been  studied  in  sufficient  detail  to 
bring  out  the  evidence  that  there  is  as  much  variation 
on  the  psychological  as  on  the  morphological  side, 
although  this  field  seems  fresh  and  inviting  when  com- 
pared with  the  researches  of  the  laboratory. 

The  necessity  of  interpreting  the  actions  of  animals 
in  terms  of  our  own  consciousness  must  be  always  with 
us.  To  interpret  them  at  all  we  must  consider  what  our 
own  mental  states  would  be  under  similar  circumstances, 
our  safeguard  being  to  keep  always  before  us  the  pro- 
gressive weakening  of  the  evidence  as  we  apply  it  to 
animals  whose  structure  is  less  and  less  like  our  own. 

We  arrange  the  activities  of  the  wasps  that  we  have 
studied  into  two  groups,  Instincts,  and  Acts  of  Intelli- 
gence, it  being  understood  that  these  classes  pass  by 
insensible  stages  into  each  other,  and  that  acts  that 
are  purely  instinctive  when  performed  for  the  first  time 
are  probably  in  some  degree  modified  by  individual 
experience.  In  this  classification  the  question  of  origin 
is  not  considered.  The  facts  are  grouped  under  the 
293 


WASPS,    SOCIAL    AND    SOLITARY 

two  heads,  the  inferences  that  they  warrant  being  left 
for  later  consideration.  Under  the  term  Instinct  we 
place  all  complex  acts  that  are  performed  previous  to 
experience  and  in  a  similar  manner  by  all  members  of 
the  same  sex  and  race,  leaving  out  as  non-essential,  at 
this  time,  the  question  of  whether  they  are  or  are  not 
accompanied  by  consciousness.  Under  Intelligence  we 
place  those  conscious  actions  which  are  more  or  less 
modifiable  by  experience.  It  is  this  power  that  enables 
an  insect  to  seek,  accept,  refuse,  choose,  —  to  decline  to 
make  use  of  this  or  to  turn  to  account  some  other  thing. 
Many  writers  prefer  the  term  Adaptation  for  these  ac- 
tivities, and  it  possesses  certain  advantages.  With  these 
definitions  in  mind,  let  us  group  the  activities  of  wasps 
under  the  two  heads. 

With  the  wasps  of  the  genus  Pelopseus  we  were  pre- 
sent on  several  occasions  when  the  young  emerged  from 
the  pupa  case  and  gnawed  their  way  out  of  the  mud  cell. 
They  were  limp,  and  their  wings  had  not  perfectly 
hardened,  and  yet  when  we  touched  them  they  tried  to 
attack  us,  thrusting  out  the  sting  and  moving  the  abdo- 
men about  in  various  directions.  These  movements 
were  well  directed,  and,  so  far  as  we  could  observe, 
quite  as  perfect  as  in  the  adult  wasp.  Stinging,  then, 
is  an  instinctive  act. 

294 


INSTINCT   AND    INTELLIGENCE 


The  particular  method  of  attack  and  capture  prac- 
ticed by  each  species  in  securing  its  prey  is  instinctive. 
Ammophila  pricks  a  number  of  gan- 
glia along  the  ventral  face  of  the 
caterpillar;  Pelopaeus,  we  believe, 
stabs  the  spider  in  the  cephalo- 
thorax,  and  probably  the  several 
species  of  Pompilus  do  the  same. 
Astata  bicolor  adopts  the  same  tac- 
tics in  capturing  her  bugs,  while  it 
is  said  of  the  flycatchers  that  they 
commonly  overcome  their  victims 
without  using  the  sting.  It  is  by  in- 
stinct, too,  that  these  wasps  take 
their  proper  food  supply,  one 
worms,  another  spiders,  a  third 
flies,  moths,  or  beetles.  So  strong 
and  deeply  seated  is  the  preference, 
that  no  fly  robber  ever  takes  spiders,  nor  will  the  ravisher 
of  the  spiders  change  to  beetles  or  bugs. 

The  mode  of  carrying  their  booty  is  a  true  instinct. 
Pompilus  takes  hold  of  her  spider  anywhere,  but  always 
drags  it  over  the  ground,  walking  backward;  Oxybelus 
clasps  her  fly  with  the  hind  legs,  while  Bembex  uses  the 
second  pair  to  hold  hers  tightly  against  the  under  side 
295 


PARALYZED  SPIDER  HUNG 
UP  ON  SORREL  BY  QUIN- 
QUENOTATUS  WHILE  SHE 
DIGS  HER  NEST 


WASPS,    SOCIAL   AND   SOLITARY 

of  her  thorax.  Each  works  after  her  own  fashion,  and 
in  a  way  that  is  uniform  for  each  species. 

The  capturing  of  the  victim  and  caring  for  it  before 
the  hole  is  made,  as  in  the  case  of  P.  quinquenotatus,  or 
the  reverse  method,  pursued  by  Astata,  Ammophila, 
Bembex,  and  others,  of  preparing  the  nest  before  the 
food  supply  is  secured,  is  certainly  instinctive  ;  as  is 
also  the  way  in  which  some  of  these  wasps  act  after 
bringing  the  prey  to  the  nest.  For  example,  S.  ichneu- 
monea  places  her  grasshopper  just  at  the  entrance  to 
the  excavation,  and  then  enters  to  see  that  all  is  right 
before  dragging  it  in.  Under  natural  conditions  this 
order  is  never  varied,  although  the  wasp  can  adapt 
herself  to  different  circumstances  when  occasion  de- 
mands. Again,  we  see  Oxybelus  scratching  open  her 
nest  while  on  the  wing,  and  entering  at  once  with  the 
fly  held  tightly  in  her  legs.  Each  way  is  characteristic 
of  the  species,  and  would  be  an  important  part  of  any 
definition  of  the  animal  based  upon  its  habits. 

The  general  style  of  the  nest  depends  upon  instinct. 
Trypoxylon  uses  hollow  passages  in  trees,  posts,  straws, 
or  brick  walls;  Diodontus  americanus,  a  member  of  the 
same  family,  always  burrows  in  the  ground,  as  do  Bem- 
bex, Ammophila,  and  Sphex.  In  the  case  of  Trypoxylon 
the  passage  may  be  ready  for  use  or  may  require  more 
296 


INSTINCT   AND    INTELLIGENCE 

or  less  preparation  ;  the  instinctive  part  is  the  impulse 
that  requires  the  insect  to  use  a  certain  kind  of  habi- 
tation. Any  one  familiar  with  T.  rubrocinctum  would 
never  look  for  her  nest  in  standing  stems  or  under 
stones;  to  use  Mr.  Morgan's  test,  he  would  be  willing 
to  bet  on  the  general  style  of  the  dwelling-place.  All  of 
these  acts  are  similarly  performed  by  individuals  of  the 
same  sex  and  race,  not  in  circumstantial  detail  but  quite 
in  the  same  way  in  a  broad  sense.  Variation  is  always 
present,  but  the  tendency  to  depart  from  a  certain  type 
is  not  excessive.  In  Cerceris  the  burrow  is  tortuous, 
this  style  of  work  being  common  to  many  species  in  the 
genus,  and  very  characteristic.  No  Sphex  nor  Ammo- 
phila  constructs  any  such  tunnel.  The  adherence  of 
all  the  members  of  a  species  to  a  certain  style  of  archi- 
tecture is,  then,  due  to  instinct. 

The  spinning  of  the  cocoon,  in  those  species  in  which 
the  larva  is  protected  in  this  manner,  and  its  shape,  are 
instinctive.  We  find  that  closely  allied  species  in  the 
same  genus  make  very  different  cocoons,  as  is  seen  in 
T.  rubrocinctum  and  T.  bidentatum.  Some  wasps  spin 
no  such  covering  for  themselves.  It  is  a  well-known 
fact  that  silkworms  sometimes  omit  the  spinning  of  a 
cocoon  ;  but  this  does  not  affect  the  argument,  since 
the  descendants  of  these  individuals  make  the  charac- 
297 


WASPS,    SOCIAL   AND    SOLITARY 

teristic  covering.  Such  cases  are  probably  due  to  indi- 
vidual variation  or  perhaps  to  atavism,  this  throwing 
back  being  not  uncommon  among  forms  that  are  well 
known. 

Not  all  of  the  instinctive  acts  here  enumerated  are 
displayed  by  each  species  studied,  although  they  are 
common  to  most  of  them.  We  have  doubtless  overlooked 
some  activities  that  should  come  under  this  head,  as 
we  have  not  made  a  thorough  study  of  any  sufficient 
number  of  species  to  make  a  final  settlement  of  the 
matter. 

As  we  have  seen  with  Ammophila  and  Pelopaeus, 
faults  of  instinct  are  not  uncommon,  but  of  all  our  wasps 
the  one  that  shows  the  greatest  aberrations  is  Pompilus 
biguttatus.  The  sandy  beach  of  Lake  Michigan  is  a 
favorite  nesting-ground  with  this  species,  and  is  the 
scene  of  many  a  bold  robbery,  since  they  are  unprin- 
cipled little  wretches  and 

"...  the  good  old  rule 

Sufficeth  them,  the  simple  plan 

That  they  should  take  who  have  the  power 

And  they  should  keep  who  can." 

We  once  found  an  unusually  tiny  biguttatus  vainly 
trying  to  drag  a  large  Epeirid  which  her  sting  had  re- 
duced to  helplessness.  It  was  as  though  a  feeble  child 


INSTINCT   AND    INTELLIGENCE 

should  try  to  move  the  body  of  an  elephant.  The  little 
wasp  clasped  one  of  the  spider's  legs  firmly  in  her  man- 
dibles, and  then  with  braced  feet  and  the  wildest  flutter 
of  wings  made  gallant  but  futile  attempts  to  get  it 
started.  Now  she  lost  her  hold  on  the  ground,  and  wings 
and  legs  were  all  whirling  desperately  in  the  air.  Now 
her  feet  grasped  a  loose  ball  of  earth,  and,  feeling  that 
something  was  moving,  she  renewed  her  efforts.  The 
pellet  was  drawn  nearer  and  began  to  rotate  around 
the  wasp,  while  she  seemed  to  be  under  the  impression 
that  she  was  moving  forward.  After  a  few  minutes  of 
vigorous  exercise,  she  paused,  perhaps  to  see  how  she 
was  getting  on,  and  the  bit  of  earth  rolled  away;  so 
that  when  the  attack  was  renewed,  it  was  under  the  old 
discouraging  conditions.  She  was  the  impersonation  of 
perseverance  and  energy;  but  after  half  an  hour  (no 
one  knows  how  long  she  had  been  at  it  before  we  came) 
she  gave  it  up,  and  with  many  reluctant  circlings  flew 
away.  It  was  probably  experiences  of  this  kind  that 
developed  in  some  of  her  relatives  the  habit  of  digging 
the  grave  under  the  victim,  and  thus  saving  the  trouble 
of  transportation. 

At  another  time,  we  saw  a  biguttatus  trying  to  run 
backward  with  a  little  bit  of  a  spider,  which  she  had 
lifted  from  the  ground  and  was  carrying  in  her  man- 
299 


WASPS,    SOCIAL   AND    SOLITARY 

dibles, — trying  to  run  backward,  because  it  is  the  rule 
with  this  genus  to  move  in  that  way  when  encumbered 
with  a  load,  it  being  easier  to  drag  a  heavy  spider  than 
to  pick  it  up  and  go  forward.  The  wasp  in  question 
was  drawn  in  two  directions.  Instinct  made  her  go 
backward,  although  in  this  particular  case  it  was  need- 
less, while  she  felt  a  constant  desire  to  turn  and  go 
straight  ahead.  As  a  result  she  waltzed  slowly  over  the 
sand  in  a  series  of  overlapping  circles,  her  head  turned 
toward  every  point  of  the  compass  in  succession,  a  kind 
of  progress  most  amusing  to  the  lookers-on. 

Biguttatus  is  not  strong  enough  to  fly  when  laden, 
but  it  is  the  habit  of  the  species  to  climb  backwards  to 
the  top  of  every  obstacle  in  the  path,  and  from  this 
vantage  point  to  gain  time  by  taking  a  downward  flight 
in  the  direction  of  the  nest.  It  is  only  in  the  case  of 
tall,  smooth-stemmed  plants  and  grasses  that  the  ad- 
vantage gained  is  enough  to  repay  the  trouble  of  climbing, 
and  we  have  often  thought  that  the  notion  costs  the  wasp 
more  trouble  than  it  is  worth,  —  as  was  certainly  the  case 
with  one  comical  little  creature  that  carried  the  idea  to 
the  extreme  of  folly.  Not  only  did  she  scale  objects  in 
her  way,  but  just  as  old  Dr.  Johnson  felt  that  he  had 
to  touch  every  tree  and  post  as  he  walked  along,  so 
when  this  wasp  saw,  out  of  the  corner  of  her  eye,  a 
300 


INSTINCT   AND    INTELLIGENCE 

stone  or  a  plant  three  or  four  inches  to  one  side,  it  called 
upon  her  to  climb,  and  climb  she  did,  although  she  was 
obliged  to  leave  her  proper  path  to  do  it. 

It  is  obviously  more  difficult  to  distinguish  actions  of 
intelligence  than  of  instinct.  One  must  be  familiar  with 
the  normal  conditions  of  the  insects  in  question  before 
he  is  able  to  note  those  slight  changes  in  the  environ- 
ment that  offer  some  opportunity  for  an  adaptation  of 
means  to  ends,  or  before  he  is  competent  to  devise  ex- 
periments which  will  test  their  powers  in  this  direction. 

We  find  two  classes  of  intelligent  actions  among  the 
Hymenoptera  which  are  sufficiently  distinct  to  be  con- 
sidered separately,  although,  like  all  natural  groups, 
they  grade  into  each  other.  The  first  of  these  includes 
those  actions  that  are  performed  by  large  numbers  in  a 
similar  fashion  under  like  conditions,  while  in  the  sec- 
ond class  each  act  is  an  individual  affair,  —  as  where  a 
single  wasp,  uninfluenced  in  any  way  by  the  example 
of  those  about  it,  displays  unusual  intelligence  in  grap- 
pling with  the  affairs  of  life.  Examples  of  the  first  class 
are  found  in  such  modifications  of  instinct  as  are  shown 
by  Pelopseus  and  other  wasps  in  the  character  of  their 
habitations.  Pelopseus,  instead  of  building  in  hollow 
trees  or  under  shelving  rocks,  as  was  the  ancient  custom 
of  the  race,  now  nests  in  chimneys,  or  under  the  eaves 
301 


WASPS,   SOCIAL   AND    SOLITARY 

of  buildings.  We  have  found  T.  rubrocinctum  taking 
advantage  of  the  face  of  a  straw-stack  that  had  been 
cut  off  smoothly  as  the  cattle  were  fed  through  the  win- 
ter. The  same  power  of  adaptation  is  shown  by  Fabre's 
experiment  with  Osmfa,  in  which  he  took  two  dozen 
nests  in  shells  from  a  quarry,  where  the  bees  had  been 
nesting  for  centuries,  and  placed  them  in  his  study 
along  with  some  empty  shells  and  some  hollow  stems. 
When  the  bees  came  out,  in  the  spring,  nearly  all  of 
them  selected  the  stalks  to  build  in  as  being  better  suited 
to  their  use  than  the  shells.  All  of  these  changes  are 
intelligent  adaptations  to  new  modes  of  life,  serving 
to  keep  the  species  in  harmony  with  its  surroundings. 
The  same  thing  may  be  seen  when  a  number  of  social 
wasps  work  together  to  replace  the  roof  of  their  nest 
when  it  has  been  torn  off. 

An  instance  of  the  second  class  is  seen  in  one  of  our 
examples  of  Pompilus  marginatus.  This  species,  while 
searching  for  a  nesting-place,  leaves  its  spider  lying  on 
the  ground  or  hides  it  under  a  lump  of  earth,  in  either 
of  which  positions  the  booty  is  subject  to  the  attacks 
of  ants ;  the  wasp  in  question  improved  upon  the  custom 
of  her  tribe  by  carrying  the  spider  up  into  a  plant  and 
hanging  it  there.  We  have  now  and  then  seen  a  queen 
of  Polistes  fusca  occupy  a  comb  of  the  previous  year 
302 


INSTINCT   AND    INTELLIGENCE 

instead  of  building  a  new  one  for  herself,  —  showing  a 
better  mental  equipment  than  her  sisters  who  were  not 
strong-minded  enough  to  change  their  ways,  and  so  built 
new  nests  alongside  of  unoccupied  old  ones  which  were 
in  good  condition.  In  Bembex  society  it  is  good  form 
to  close  the  door  on  leaving  home,  but  sometimes  a 
wasp  will  save  time  by  leaving  the  entrance  open.  This, 
however,  is  a  doubtful  case,  as  the  advantage  would, 
perhaps,  be  more  than  balanced  by  the  exposure  of  the 
nest  to  parasites. 

Some  years  after  our  first  experience  with  Pompilus 
scelestus  we  saw  a  wasp  of  this  species  carrying  her  spider 
home.  She  dropped  it  close  to  the  nest,  and  looked 
meditatively,  first  at  the  hole  and  then  at  the  spider.  It 
was  unquestionably  going  to  be  a  very  tight  fit,  but  if 
she  could  get  it  in  that  would  be  an  advantage;  so  after 
a  moment  she  seized  it  by  the  tip  of  the  abdomen  and 
backing  down  tried  to  pull  it  after.  Tug  —  tug  !  No,  it 
would  not  go  down,  and  scelestus  pushed  it  out  and 
carried  it  to  a  place  of  safety  up  among  some  clover 
blossoms.  She  then  washed  and  brushed  herself  neatly, 
and  took  several  little  walks,  so  that  it  was  fully  fifteen 
minutes  before  she  began  to  enlarge  her  nest.  All  that 
time  she  must  have  carried  in  her  little  scrap  of  a  mind 
the  idea  of  doing  a  necessary  act  which  was  outside  of 
303 


WASPS,    SOCIAL   AND   SOLITARY 

her  ordinary  routine;  and  we  noted  with  interest  that  the 
change  when  it  was  made  accomplished  exactly  what 
was  needed,  —  the  spider  went  in,  but  not  too  easily. 

In  an  experiment  with  a  French  Sphex  which  has 
the  habit  of  laying  her  cricket  down  at  the  threshold, 
and  going  inside  for  an  instant  before  dragging  it  in, 
Fabre  took  advantage  of  the  moment  that  the  wasp 
was  out  of  sight  below  to  move  her  prey  to  a  little  dis- 
tance, with  the  result  that  when  the  wasp  came  up  she 
brought  her  cricket  to  the  same  spot  and  left  it  as  be- 
fore, while  she  visited  the  interior  of  the  nest.  Since  he 
repeated  this  experiment  about  forty  times  and  always 
with  the  same  result,  it  seemed  fair  to  draw  the  con- 
clusion that  nothing  less  than  the  performance  of  a 
certain  series  of  acts  in  a  certain  order  would  satisfy 
her  impulse.  She  must  place  her  prey  just  so  close  to  the 
doorway;  she  must  then  descend  to  examine  the  nest; 
and  after  that  she  must  at  once  drag  it  down,  any  dis- 
turbance of  this  routine  causing  her  to  refuse  to  proceed. 
We  once  found  a  Sphex  ichneumonea  at  work  storing 
her  nest,  and  thought  it  would  be  interesting  to  pursue 
Fabre's  method  and  find  out  whether  she  were  equally 
persistent  in  following  her  regular  routine.  We  allowed 
her  to  carry  in  one  grasshopper  to  establish  her  normal 
method  of  procedure,  and  found  that,  bringing  it  on  the 
304 


INSTINCT   AND   INTELLIGENCE 

wing,  she  dropped  it  about  six  inches  away,  ran  into  the 
nest,  out  again  and  over  to  the  grasshopper,  which  she 
straddled  and  carried  by  the  head  to  the  entrance. 
She  then  ran  down  head  first,  turned  around,  came  up, 
and  seizing  it  by  the  head,  pulled  it  within.  On  the 
following  day,  when  she  had  brought  a  grasshopper  to 
the  entrance  of  the  nest,  and  while  she  was  below,  we 
moved  it  back  five  or  six  inches.  When  she  came  out, 
she  carried  it  to  the  same  spot  and  went  down  as  before. 
We  removed  it  again,  with  the  same  result,  and  the 
performance  was  repeated  a  third  and  a  fourth  tune, 
but  the  fifth  time  that  she  had  found  her  prey  where  we 
had  placed  it  she  seized  it  by  the  head,  and  going  back- 
ward dragged  it  down  into  the  nest  without  pausing. 
On  the  next  day  the  experiment  was  repeated.  After 
we  had  moved  the  grasshopper  away  four  times,  she 
carried  it  into  the  nest,  going  head  foremost.  On  the 
fourth  and  last  day  of  our  experiment,  she  replaced  the 
grasshopper  at  the  door  of  the  nest  and  ran  inside  seven 
times,  but  then  seized  it  and  dragged  it  in,  going  back- 
ward. How  shall  this  change  in  a  long-established 
custom  be  explained,  except  by  saying  that  her  intelli- 
gence led  her  to  adapt  herself  to  circumstances?  She 
was  enough  of  a  conservative  to  prefer  the  old  way,  but 
was  not  such  a  slave  to  custom  as  to  be  unable  to  vary  it. 
I  305 


WASPS,    SOCIAL   AND    SOLITARY 

"It  hath  been  an  opinion,"  says  Lord  Bacon,  "that 
the  French  are  wiser  than  they  seem,  while  the  Spaniards 
seem  wiser  than  they  are."  We  leave  it  to  our  readers 
to  determine  whether  the  wasps,  are  wiser  than  they 
seem  or  seem  wiser  than  they  are. 


INDEX 


INDEX 

AGENIA,    mutilation    of    spiders,  j  Belt,  Thomas,  on  locality  study  of 
243,  247.  Polistes  carnifex,  60. 

—  bombycina,  244.  i  Bembex  labiatus,  note  on  locality 

Ammophila,  15  ;  stinging  habits  of  '      sense  by  Bouvier,  124. 

American  and  French  species,  j rostrata,   account   of   habits 

28;  Fabre's  conclusions  con- [  by  Wesenberg,  139;  note  on 
trasted  with  ours,  52 ;  sleeping  |  locality  sense  by  Marchand, 
habits  noted  by  Banks,  117.  125. 

gracilis,  great  distance  over  j spinolae,  119;  less  numerous 

which  prey  is  carried,  46 ;  failure  !  progeny  than  other  wasps,  1 20 ; 
of  instinct,  46.  habit  of  feeding  young  from 

polita,  50.  i      day  to  day,  1 20  ;    quarrelsome 

urnaria,  18;  sense  of  locality,        habits,  129;  tolerance  of  para- 

20 ;  individuality,  22;  using  a!  sites,  132;  number  of  parasitic 
pebble  as  a  tool,  38.  |  larvae  found  in  nests,  133;  ex- 

vulgaris,  losing  her  way,  46.    j      periment  to  determine  number 

yarrowii,  Williston's  notes  on       of  nests  visited  by  female  at  one 

habits,  40.  :      time,  139;  teasing  Tachysphex, 

Aphilanthops  frigidus,   167;   los- j      262. 

ing  her  way,   171 ;  method   of  j  Bouvier,  note  on  locality  sense  of 

capturing  queen  ants  uncertain,  '      Bembex  labiatus,  124. 

174.  j  Brehm,  on  mutilation   of  spiders 

Aporus   fasciatus,   80  ;    habit   of  j      by  Agenia  punctata,  243. 

filling   up    partly    made   nests,    Brues,  on  sleeping  habits  of  Prio- 

82;    depends  upon  close  pack-  j      nonyx  atrata,  118. 

ing  to   keep   spider  quiet,  83 ; 

contrast  between   two  individ-    Cerceris    clypeata,    147  ;    locality 


uals,  84. 
Ashmead,   W.   H.,  on  European 


study,    149  ;     experiments    on 
stinging  habits,  151. 


species  of  Oxybelus,  78.  j deserta,  152;  locality  study, 

Astata  bicolor,  locality  study,  288.  j      1 53. 

unicolor,  locality  study,  290.  | fumipennis,  142. 

• nigrescens,  142. 

Banks,    Nathan,  observation    on  i  Ceropales,     following     Pompilus 

sleeping  habits  of  Ammophila,  j      scelestus,  231. 

117.  Chlorion  coeruleum,  256. 


Bates,  H.  W.,  on  habits  of  Mone- 
dula  signata,  136. 


Crabro  interruptus,  102;  locality 
study,  105. 


309 


INDEX 


Crabro  lentus,  101  ;  both  flies  and 
bugs  found  in  nests,  101. 

sexmaculatus,  99 ;  takes  both 

flies  and  gnats,  101. 

stirpicola,  106  ;  contrasted 

with  other  wasps  as  to  manner, 
106;  works  night  and  day  to 
finish  nest,  108. 

wesmaeli,  said  to  take  both 

flies  and  bugs,  101. 

Dunning,  S.  W.,  on  finding  flies 
alive  in  nests  of  Bembex,  135. 

Fabre,  J.  H.,  on  automatically 
perfect  instincts  of  Ammophila, 

fz  ;     on    French     species     of 
phex,  69;    on   the   habits   of 
Bembex,  134  ;    on   Philanthus 
apivorus,     162  ;      on     French 
species  of  Pelopaeus,  273. 

Goureau,  on  mutilation  of  spiders 
by  wasps,  244. 

Larra  quebecensis,  263. 

Lubbock,  Sir  John,  on  individu- 
ality in  ants,  288. 

Lyroda  subita,  253;  feeds  her 
young  from  day  to  day,  255. 

Marchal,  Paul,  on   poor   locality 

sense   of    Pompilus    seriaceus, 

284. 
Marchand,  observation  on  locality 

sense  of  Bembex  rostrata,  125. 
Monedula  signata,  locality  study 

noted  by  Bates,  136. 
Mutilation  of   spiders   by  wasps, 

243- 

Odynerus,    variation    in    nesting 

habits,  95. 
anormis,  position   of  egg  in 

nest,  91. 

capra,  94. 

conformis,  position  of   egg, 

91. 


Odynenis  perennis,  89. 

reniformis,  position  of  egg, 

90. 

vagus,  wariness,  94. 

Oxybelus  quadrinotatus,  75;  me- 
thod of  carrying  fly,  80. 

Passolocus  annulatus,  87. 

Pelopaeus,  265 ;  individuality,  270 ; 
forgetfulness,  27 1 ;  difference 
between  French  and  American 
species,  273. 

Philanthus  apivorus,  sucks  honey 
from  bee,  162. 

punctatus,  154;  habits  of 

colony,  1 56 ;  experiments  on 
stinging  habits,  162;  nesting 
habits  of  males,  166. 

ventilabris,  166. 

Plenolocus  peckhamii,  95;  stalk 
invaded  by  bees  and  other 
wasps,  96. 

Polistes  carnifex,  locality  study 
noted  by  Belt,  60. 

Pompilus  biguttatus,  unreasoning 
conduct,  298. 

fuscipennis,  216;  afraid  of 

ants,  219;  biting  legs  of  spider, 
220;  sense  of  locality,  221. 

marginatus,  22 1  ;  capturing 

spider,  225 ;  method  of  digging 
nest,  229. 

quinquenotatus,  197;  con- 
fined to  one  species  of  spider, 
202 ;  nest  invaded  by  small 
ants,  202  ;  hangs  spider  on 
plant  while  nest  is  being  made, 
204 ;  robs  her  neighbors,  211; 
loses  her  way,  214. 

scelestus,  230;  bites  legs  of 

spider,  230;  pursued  by  para- 
sites, 231 ;  sleeping  habits,  236. 

seriaceus,  poor  locality  sense 

noted  by  Marchal,  284. 

subviolaceus,  following  sce- 
lestus, 236. 

Priononyx  atrata,  note  on  sleep- 
ing habits,  1 1 8. 


3IO 


INDEX 


Rhopalum  pedicellatum,  73 ; 
strong  power  of  localization, 

73- 
rubrocinctum,  74. 

Social  wasps,  general  habits,  3 ; 
color  sense.  5 ;  sense  of  smell, 
8 ;  affecting  plant  distribution, 
1 1 ;  number  in  one  nest,  1 2. 

Solitary  wasps,  general  habits,  1 5. 

Sphex,  habits  noted  by  Fabre, 
69. 

ichneumonea,  56;  nests  be- 
gun and  deserted,  56;  locality 
study,  58 ;  intelligence,  305. 

Tachysphex  tarsata,  261. 
Tachytes  sp.  ?,  248. 
peptonica,  252. 


Trypoxylon,  immense  numbers  of 
spiders  destroyed,  195. 

albopilosum,  190. 

bidentatum,  194. 

rubrocinctum,  180;  protec- 
tion of  nest  by  male,  181 ;  male 
sometimes  assists  in  storing 
nest,  182;  order  in  which  eggs 
hatch,  180. 

Vespa  germanica,  13. 
maculata,  13. 

Wesenberg,   on   habits   of  Bem- 

bex  rostrata,  139. 
Wheeler,  W.  M.,on  captureof  ants 

by  Aphilanthops  frigidus,  176. 
Williston,  S.    W.,   on   habits   of 

Ammophila  yarrowii,  40. 


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